diff --git a/atom/browser/api/atom_api_window.cc b/atom/browser/api/atom_api_window.cc
index 0b2c8c9ece79..6ff1dfc00628 100644
--- a/atom/browser/api/atom_api_window.cc
+++ b/atom/browser/api/atom_api_window.cc
@@ -18,14 +18,20 @@
 #include "native_mate/dictionary.h"
 #include "ui/gfx/geometry/rect.h"
 
+#if defined(OS_WIN)
+#include "atom/browser/native_window_views.h"
+#include "atom/browser/ui/win/taskbar_host.h"
+#endif
+
 #include "atom/common/node_includes.h"
 
+#if defined(OS_WIN)
 namespace mate {
 
 template<>
-struct Converter<atom::NativeWindow::ThumbarButton> {
+struct Converter<atom::TaskbarHost::ThumbarButton> {
   static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val,
-                     atom::NativeWindow::ThumbarButton* out) {
+                     atom::TaskbarHost::ThumbarButton* out) {
     mate::Dictionary dict;
     if (!ConvertFromV8(isolate, val, &dict))
       return false;
@@ -37,6 +43,7 @@ struct Converter<atom::NativeWindow::ThumbarButton> {
 };
 
 }  // namespace mate
+#endif
 
 namespace atom {
 
@@ -431,9 +438,19 @@ void Window::SetOverlayIcon(const gfx::Image& overlay,
   window_->SetOverlayIcon(overlay, description);
 }
 
-void Window::SetThumbarButtons(
-    const std::vector<NativeWindow::ThumbarButton>& buttons) {
-  window_->SetThumbarButtons(buttons);
+bool Window::SetThumbarButtons(mate::Arguments* args) {
+#if defined(OS_WIN)
+  std::vector<TaskbarHost::ThumbarButton> buttons;
+  if (!args->GetNext(&buttons)) {
+    args->ThrowError();
+    return false;
+  }
+  auto window = static_cast<NativeWindowViews*>(window_.get());
+  return window->taskbar_host().SetThumbarButtons(
+      window->GetAcceleratedWidget(), buttons);
+#else
+  return false;
+#endif
 }
 
 void Window::SetMenu(v8::Isolate* isolate, v8::Local<v8::Value> value) {
diff --git a/atom/browser/api/atom_api_window.h b/atom/browser/api/atom_api_window.h
index 7742c8a9fa9b..de2f093ea3e1 100644
--- a/atom/browser/api/atom_api_window.h
+++ b/atom/browser/api/atom_api_window.h
@@ -130,8 +130,7 @@ class Window : public mate::TrackableObject<Window>,
   void SetProgressBar(double progress);
   void SetOverlayIcon(const gfx::Image& overlay,
                       const std::string& description);
-  void SetThumbarButtons(
-      const std::vector<NativeWindow::ThumbarButton>& buttons);
+  bool SetThumbarButtons(mate::Arguments* args);
   void SetMenu(v8::Isolate* isolate, v8::Local<v8::Value> menu);
   void SetAutoHideMenuBar(bool auto_hide);
   bool IsMenuBarAutoHide();
diff --git a/atom/browser/native_window.cc b/atom/browser/native_window.cc
index 91770af316e3..96085846bca8 100644
--- a/atom/browser/native_window.cc
+++ b/atom/browser/native_window.cc
@@ -277,11 +277,6 @@ bool NativeWindow::HasModalDialog() {
   return has_dialog_attached_;
 }
 
-bool NativeWindow::SetThumbarButtons(
-    const std::vector<ThumbarButton>& buttons) {
-  return false;
-}
-
 void NativeWindow::FocusOnWebView() {
   web_contents()->GetRenderViewHost()->Focus();
 }
diff --git a/atom/browser/native_window.h b/atom/browser/native_window.h
index d461215222d6..b9294d38c931 100644
--- a/atom/browser/native_window.h
+++ b/atom/browser/native_window.h
@@ -60,14 +60,6 @@ class NativeWindow : public content::WebContentsObserver,
                      public brightray::InspectableWebContentsViewDelegate {
  public:
   using CapturePageCallback = base::Callback<void(const SkBitmap& bitmap)>;
-  using ThumbarButtonClickedCallback = base::Closure;
-
-  struct ThumbarButton {
-    std::string tooltip;
-    gfx::Image icon;
-    std::vector<std::string> flags;
-    ThumbarButtonClickedCallback clicked_callback;
-  };
 
   class DialogScope {
    public:
@@ -103,6 +95,7 @@ class NativeWindow : public content::WebContentsObserver,
 
   virtual void Close() = 0;
   virtual void CloseImmediately() = 0;
+  virtual bool IsClosed() const { return is_closed_; }
   virtual void Focus(bool focus) = 0;
   virtual bool IsFocused() = 0;
   virtual void Show() = 0;
@@ -147,16 +140,17 @@ class NativeWindow : public content::WebContentsObserver,
   virtual void SetMenu(ui::MenuModel* menu);
   virtual bool HasModalDialog();
   virtual gfx::NativeWindow GetNativeWindow() = 0;
+
+  // Taskbar/Dock APIs.
   virtual void SetProgressBar(double progress) = 0;
   virtual void SetOverlayIcon(const gfx::Image& overlay,
                               const std::string& description) = 0;
+
+  // Workspace APIs.
   virtual void SetVisibleOnAllWorkspaces(bool visible) = 0;
   virtual bool IsVisibleOnAllWorkspaces() = 0;
-  virtual bool SetThumbarButtons(
-      const std::vector<ThumbarButton>& buttons);
-
-  virtual bool IsClosed() const { return is_closed_; }
 
+  // Webview APIs.
   virtual void FocusOnWebView();
   virtual void BlurWebView();
   virtual bool IsWebViewFocused();
diff --git a/atom/browser/native_window_views.cc b/atom/browser/native_window_views.cc
index acb7de33f4d6..45697c96683c 100644
--- a/atom/browser/native_window_views.cc
+++ b/atom/browser/native_window_views.cc
@@ -4,10 +4,6 @@
 
 #include "atom/browser/native_window_views.h"
 
-#if defined(OS_WIN)
-#include <shobjidl.h>
-#endif
-
 #include <string>
 #include <vector>
 
@@ -46,13 +42,9 @@
 #elif defined(OS_WIN)
 #include "atom/browser/ui/views/win_frame_view.h"
 #include "atom/browser/ui/win/atom_desktop_window_tree_host_win.h"
-#include "base/win/scoped_comptr.h"
-#include "base/win/windows_version.h"
 #include "ui/base/win/shell.h"
-#include "ui/gfx/icon_util.h"
 #include "ui/gfx/win/dpi.h"
 #include "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
-#include "ui/views/win/hwnd_util.h"
 #endif
 
 namespace atom {
@@ -221,11 +213,11 @@ NativeWindowViews::NativeWindowViews(
   params.native_widget =
       new views::DesktopNativeWidgetAura(window_.get());
   atom_desktop_window_tree_host_win_ = new AtomDesktopWindowTreeHostWin(
+      this,
       window_.get(),
       static_cast<views::DesktopNativeWidgetAura*>(params.native_widget));
   params.desktop_window_tree_host = atom_desktop_window_tree_host_win_;
-#endif
-#if defined(USE_X11)
+#elif defined(USE_X11)
   std::string name = Browser::Get()->GetName();
   // Set WM_WINDOW_ROLE.
   params.wm_role_name = "browser-window";
@@ -621,24 +613,7 @@ gfx::NativeWindow NativeWindowViews::GetNativeWindow() {
 
 void NativeWindowViews::SetProgressBar(double progress) {
 #if defined(OS_WIN)
-  if (base::win::GetVersion() < base::win::VERSION_WIN7)
-    return;
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  if (FAILED(taskbar.CreateInstance(CLSID_TaskbarList, NULL,
-                                    CLSCTX_INPROC_SERVER) ||
-      FAILED(taskbar->HrInit()))) {
-    return;
-  }
-  HWND frame = views::HWNDForNativeWindow(GetNativeWindow());
-  if (progress > 1.0) {
-    taskbar->SetProgressState(frame, TBPF_INDETERMINATE);
-  } else if (progress < 0) {
-    taskbar->SetProgressState(frame, TBPF_NOPROGRESS);
-  } else if (progress >= 0) {
-    taskbar->SetProgressValue(frame,
-                              static_cast<int>(progress * 100),
-                              100);
-  }
+  taskbar_host_.SetProgressBar(GetAcceleratedWidget(), progress);
 #elif defined(USE_X11)
   if (unity::IsRunning()) {
     unity::SetProgressFraction(progress);
@@ -649,22 +624,7 @@ void NativeWindowViews::SetProgressBar(double progress) {
 void NativeWindowViews::SetOverlayIcon(const gfx::Image& overlay,
                                        const std::string& description) {
 #if defined(OS_WIN)
-  if (base::win::GetVersion() < base::win::VERSION_WIN7)
-    return;
-
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  if (FAILED(taskbar.CreateInstance(CLSID_TaskbarList, NULL,
-                                    CLSCTX_INPROC_SERVER) ||
-      FAILED(taskbar->HrInit()))) {
-    return;
-  }
-
-  HWND frame = views::HWNDForNativeWindow(GetNativeWindow());
-
-  std::wstring wstr = std::wstring(description.begin(), description.end());
-  taskbar->SetOverlayIcon(frame,
-      IconUtil::CreateHICONFromSkBitmap(overlay.AsBitmap()),
-      wstr.c_str());
+  taskbar_host_.SetOverlayIcon(GetAcceleratedWidget(), overlay, description);
 #endif
 }
 
@@ -717,18 +677,6 @@ bool NativeWindowViews::IsVisibleOnAllWorkspaces() {
   return false;
 }
 
-bool NativeWindowViews::SetThumbarButtons(
-    const std::vector<NativeWindow::ThumbarButton>& buttons) {
-#if defined(OS_WIN)
-  if (atom_desktop_window_tree_host_win_) {
-    return atom_desktop_window_tree_host_win_->SetThumbarButtons(
-        views::HWNDForNativeWindow(window_->GetNativeWindow()),
-        buttons);
-  }
-#endif
-  return false;
-}
-
 gfx::AcceleratedWidget NativeWindowViews::GetAcceleratedWidget() {
   return GetNativeWindow()->GetHost()->GetAcceleratedWidget();
 }
@@ -890,6 +838,17 @@ void NativeWindowViews::GetDevToolsWindowWMClass(
 }
 #endif
 
+#if defined(OS_WIN)
+bool NativeWindowViews::PreHandleMSG(
+    UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) {
+  // Handle thumbar button click message.
+  if (message == WM_COMMAND && HIWORD(w_param) == THBN_CLICKED)
+    return taskbar_host_.HandleThumbarButtonEvent(LOWORD(w_param));
+  else
+    return false;
+}
+#endif
+
 void NativeWindowViews::HandleKeyboardEvent(
     content::WebContents*,
     const content::NativeWebKeyboardEvent& event) {
diff --git a/atom/browser/native_window_views.h b/atom/browser/native_window_views.h
index 792a72c75624..355f5bd38ef3 100644
--- a/atom/browser/native_window_views.h
+++ b/atom/browser/native_window_views.h
@@ -14,6 +14,11 @@
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/views/widget/widget_observer.h"
 
+#if defined(OS_WIN)
+#include "atom/browser/ui/win/message_handler_delegate.h"
+#include "atom/browser/ui/win/taskbar_host.h"
+#endif
+
 namespace views {
 class UnhandledKeyboardEventHandler;
 }
@@ -23,11 +28,15 @@ namespace atom {
 class GlobalMenuBarX11;
 class MenuBar;
 class WindowStateWatcher;
+
 #if defined(OS_WIN)
 class AtomDesktopWindowTreeHostWin;
 #endif
 
 class NativeWindowViews : public NativeWindow,
+#if defined(OS_WIN)
+                          public MessageHandlerDelegate,
+#endif
                           public views::WidgetDelegateView,
                           public views::WidgetObserver {
  public:
@@ -82,13 +91,15 @@ class NativeWindowViews : public NativeWindow,
   bool IsMenuBarVisible() override;
   void SetVisibleOnAllWorkspaces(bool visible) override;
   bool IsVisibleOnAllWorkspaces() override;
-  bool SetThumbarButtons(
-      const std::vector<NativeWindow::ThumbarButton>& buttons) override;
 
   gfx::AcceleratedWidget GetAcceleratedWidget();
 
   views::Widget* widget() const { return window_.get(); }
 
+#if defined(OS_WIN)
+  TaskbarHost& taskbar_host() { return taskbar_host_; }
+#endif
+
  private:
   // views::WidgetObserver:
   void OnWidgetActivationChanged(
@@ -127,6 +138,12 @@ class NativeWindowViews : public NativeWindow,
       std::string* name, std::string* class_name) override;
 #endif
 
+#if defined(OS_WIN)
+  // MessageHandlerDelegate:
+  bool PreHandleMSG(
+      UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) override;
+#endif
+
   // NativeWindow:
   void HandleKeyboardEvent(
       content::WebContents*,
@@ -164,6 +181,8 @@ class NativeWindowViews : public NativeWindow,
   // Records window was whether restored from minimized state or maximized
   // state.
   bool is_minimized_;
+  // In charge of running taskbar related APIs.
+  TaskbarHost taskbar_host_;
 #endif
 
   // Handles unhandled keyboard messages coming back from the renderer process.
diff --git a/atom/browser/ui/win/atom_desktop_window_tree_host_win.cc b/atom/browser/ui/win/atom_desktop_window_tree_host_win.cc
index 157cb610fb3a..84a6d9aa3e50 100644
--- a/atom/browser/ui/win/atom_desktop_window_tree_host_win.cc
+++ b/atom/browser/ui/win/atom_desktop_window_tree_host_win.cc
@@ -4,48 +4,25 @@
 
 #include "atom/browser/ui/win/atom_desktop_window_tree_host_win.h"
 
-#include <shobjidl.h>
-
-#include "atom/browser/native_window.h"
-#include "atom/browser/ui/win/thumbar_host.h"
+#include "atom/browser/ui/win/message_handler_delegate.h"
 
 namespace atom {
 
 AtomDesktopWindowTreeHostWin::AtomDesktopWindowTreeHostWin(
+    MessageHandlerDelegate* delegate,
     views::internal::NativeWidgetDelegate* native_widget_delegate,
     views::DesktopNativeWidgetAura* desktop_native_widget_aura)
         : views::DesktopWindowTreeHostWin(native_widget_delegate,
-                                          desktop_native_widget_aura) {
+                                          desktop_native_widget_aura),
+          delegate_(delegate) {
 }
 
 AtomDesktopWindowTreeHostWin::~AtomDesktopWindowTreeHostWin() {
 }
 
-bool AtomDesktopWindowTreeHostWin::SetThumbarButtons(
-    HWND window,
-    const std::vector<NativeWindow::ThumbarButton>& buttons) {
-  if (!thumbar_host_.get()) {
-    thumbar_host_.reset(new ThumbarHost(window));
-  }
-  return thumbar_host_->SetThumbarButtons(buttons);
-}
-
-bool AtomDesktopWindowTreeHostWin::PreHandleMSG(UINT message,
-                                                WPARAM w_param,
-                                                LPARAM l_param,
-                                                LRESULT* result) {
-  switch (message) {
-    case WM_COMMAND: {
-       // Handle thumbar button click message.
-       int id = LOWORD(w_param);
-       int thbn_message = HIWORD(w_param);
-       if (thbn_message == THBN_CLICKED && thumbar_host_ &&
-           thumbar_host_->HandleThumbarButtonEvent(id))
-         return true;
-    }
-  }
-
-  return false;
+bool AtomDesktopWindowTreeHostWin::PreHandleMSG(
+    UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) {
+  return delegate_->PreHandleMSG(message, w_param, l_param, result);
 }
 
 }  // namespace atom
diff --git a/atom/browser/ui/win/atom_desktop_window_tree_host_win.h b/atom/browser/ui/win/atom_desktop_window_tree_host_win.h
index fc09b6503b80..47e4cb6aed2a 100644
--- a/atom/browser/ui/win/atom_desktop_window_tree_host_win.h
+++ b/atom/browser/ui/win/atom_desktop_window_tree_host_win.h
@@ -10,31 +10,28 @@
 #include <vector>
 
 #include "atom/browser/native_window.h"
-#include "atom/browser/ui/win/thumbar_host.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host_win.h"
 
 namespace atom {
 
+class MessageHandlerDelegate;
+
 class AtomDesktopWindowTreeHostWin : public views::DesktopWindowTreeHostWin {
  public:
   AtomDesktopWindowTreeHostWin(
+      MessageHandlerDelegate* delegate,
       views::internal::NativeWidgetDelegate* native_widget_delegate,
       views::DesktopNativeWidgetAura* desktop_native_widget_aura);
-  ~AtomDesktopWindowTreeHostWin();
-
-  bool SetThumbarButtons(
-      HWND window,
-      const std::vector<NativeWindow::ThumbarButton>& buttons);
+  ~AtomDesktopWindowTreeHostWin() override;
 
  protected:
-  bool PreHandleMSG(UINT message,
-                    WPARAM w_param,
-                    LPARAM l_param,
-                    LRESULT* result) override;
+  bool PreHandleMSG(
+      UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) override;
 
  private:
-  scoped_ptr<ThumbarHost> thumbar_host_;
+  MessageHandlerDelegate* delegate_;  // weak ref
+
+  DISALLOW_COPY_AND_ASSIGN(AtomDesktopWindowTreeHostWin);
 };
 
 }  // namespace atom
diff --git a/atom/browser/ui/win/message_handler_delegate.cc b/atom/browser/ui/win/message_handler_delegate.cc
new file mode 100644
index 000000000000..791d1fd816d9
--- /dev/null
+++ b/atom/browser/ui/win/message_handler_delegate.cc
@@ -0,0 +1,14 @@
+// Copyright (c) 2015 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/browser/ui/win/message_handler_delegate.h"
+
+namespace atom {
+
+bool MessageHandlerDelegate::PreHandleMSG(
+    UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) {
+  return false;
+}
+
+}  // namespace atom
diff --git a/atom/browser/ui/win/message_handler_delegate.h b/atom/browser/ui/win/message_handler_delegate.h
new file mode 100644
index 000000000000..d8cfcf7fc43b
--- /dev/null
+++ b/atom/browser/ui/win/message_handler_delegate.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2015 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_UI_WIN_MESSAGE_HANDLER_DELEGATE_H_
+#define ATOM_BROWSER_UI_WIN_MESSAGE_HANDLER_DELEGATE_H_
+
+#include <windows.h>
+
+namespace atom {
+
+class MessageHandlerDelegate {
+ public:
+  // Catch-all message handling and filtering. Called before
+  // HWNDMessageHandler's built-in handling, which may pre-empt some
+  // expectations in Views/Aura if messages are consumed. Returns true if the
+  // message was consumed by the delegate and should not be processed further
+  // by the HWNDMessageHandler. In this case, |result| is returned. |result| is
+  // not modified otherwise.
+  virtual bool PreHandleMSG(
+      UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_UI_WIN_MESSAGE_HANDLER_DELEGATE_H_
diff --git a/atom/browser/ui/win/taskbar_host.cc b/atom/browser/ui/win/taskbar_host.cc
new file mode 100644
index 000000000000..c728e4664c3a
--- /dev/null
+++ b/atom/browser/ui/win/taskbar_host.cc
@@ -0,0 +1,165 @@
+// Copyright (c) 2015 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/browser/ui/win/taskbar_host.h"
+
+#include <string>
+
+#include "base/stl_util.h"
+#include "base/win/scoped_gdi_object.h"
+#include "base/strings/utf_string_conversions.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/icon_util.h"
+
+namespace atom {
+
+namespace {
+
+// From MSDN: https://msdn.microsoft.com/en-us/library/windows/desktop/dd378460(v=vs.85).aspx#thumbbars
+// The thumbnail toolbar has a maximum of seven buttons due to the limited room.
+const size_t kMaxButtonsCount = 7;
+
+// The base id of Thumbar button.
+const int kButtonIdBase = 40001;
+
+bool GetThumbarButtonFlags(const std::vector<std::string>& flags,
+                           THUMBBUTTONFLAGS* out) {
+  THUMBBUTTONFLAGS result = THBF_ENABLED;  // THBF_ENABLED == 0
+  for (const auto& flag : flags) {
+    if (flag == "disabled")
+      result |= THBF_DISABLED;
+    else if (flag == "dismissonclick")
+      result |= THBF_DISMISSONCLICK;
+    else if (flag == "nobackground")
+      result |= THBF_NOBACKGROUND;
+    else if (flag == "hidden")
+      result |= THBF_HIDDEN;
+    else if (flag == "noninteractive")
+      result |= THBF_NONINTERACTIVE;
+    else
+      return false;
+  }
+  *out = result;
+  return true;
+}
+
+}  // namespace
+
+TaskbarHost::TaskbarHost() : thumbar_buttons_added_(false) {
+}
+
+TaskbarHost::~TaskbarHost() {
+}
+
+bool TaskbarHost::SetThumbarButtons(
+    HWND window, const std::vector<ThumbarButton>& buttons) {
+  if (!InitailizeTaskbar())
+    return false;
+
+  callback_map_.clear();
+
+  // The number of buttons in thumbar can not be changed once it is created,
+  // so we have to claim kMaxButtonsCount buttons initialy in case users add
+  // more buttons later.
+  base::win::ScopedHICON icons[kMaxButtonsCount] = {};
+  THUMBBUTTON thumb_buttons[kMaxButtonsCount] = {};
+
+  for (size_t i = 0; i < kMaxButtonsCount; ++i) {
+    THUMBBUTTON& thumb_button = thumb_buttons[i];
+
+    // Set ID.
+    thumb_button.iId = kButtonIdBase + i;
+    thumb_button.dwMask = THB_FLAGS;
+
+    if (i >= buttons.size()) {
+      // This button is used to occupy the place in toolbar, and it does not
+      // show.
+      thumb_button.dwFlags = THBF_HIDDEN;
+      continue;
+    }
+
+    // This button is user's button.
+    const ThumbarButton& button = buttons[i];
+
+    // Generate flags.
+    thumb_button.dwFlags = THBF_ENABLED;
+    if (!GetThumbarButtonFlags(button.flags, &thumb_button.dwFlags))
+      return false;
+
+    // Set icon.
+    if (!button.icon.IsEmpty()) {
+      thumb_button.dwMask |= THB_ICON;
+      icons[i] = IconUtil::CreateHICONFromSkBitmap(button.icon.AsBitmap());
+      thumb_button.hIcon = icons[i].Get();
+    }
+
+    // Set tooltip.
+    if (!button.tooltip.empty()) {
+      thumb_button.dwMask |= THB_TOOLTIP;
+      wcscpy_s(thumb_button.szTip, base::UTF8ToUTF16(button.tooltip).c_str());
+    }
+
+    // Save callback.
+    callback_map_[thumb_button.iId] = button.clicked_callback;
+  }
+
+  // Finally add them to taskbar.
+  HRESULT r;
+  if (thumbar_buttons_added_)
+    r = taskbar_->ThumbBarUpdateButtons(window, kMaxButtonsCount,
+                                        thumb_buttons);
+  else
+    r = taskbar_->ThumbBarAddButtons(window, kMaxButtonsCount, thumb_buttons);
+
+  thumbar_buttons_added_ = true;
+  return SUCCEEDED(r);
+}
+
+bool TaskbarHost::SetProgressBar(HWND window, double value) {
+  if (!InitailizeTaskbar())
+    return false;
+
+  HRESULT r;
+  if (value > 1.0)
+    r = taskbar_->SetProgressState(window, TBPF_INDETERMINATE);
+  else if (value < 0)
+    r = taskbar_->SetProgressState(window, TBPF_NOPROGRESS);
+  else
+    r = taskbar_->SetProgressValue(window, static_cast<int>(value * 100), 100);
+  return SUCCEEDED(r);
+}
+
+bool TaskbarHost::SetOverlayIcon(
+    HWND window, const gfx::Image& overlay, const std::string& text) {
+  if (!InitailizeTaskbar())
+    return false;
+
+  base::win::ScopedHICON icon(
+      IconUtil::CreateHICONFromSkBitmap(overlay.AsBitmap()));
+  return SUCCEEDED(
+      taskbar_->SetOverlayIcon(window, icon, base::UTF8ToUTF16(text).c_str()));
+}
+
+bool TaskbarHost::HandleThumbarButtonEvent(int button_id) {
+  if (ContainsKey(callback_map_, button_id)) {
+    auto callback = callback_map_[button_id];
+    if (!callback.is_null())
+      callback.Run();
+    return true;
+  }
+  return false;
+}
+
+bool TaskbarHost::InitailizeTaskbar() {
+  if (FAILED(taskbar_.CreateInstance(CLSID_TaskbarList,
+                                     nullptr,
+                                     CLSCTX_INPROC_SERVER)) ||
+      FAILED(taskbar_->HrInit())) {
+    return false;
+  } else {
+    return true;
+  }
+}
+
+}  // namespace atom
diff --git a/atom/browser/ui/win/taskbar_host.h b/atom/browser/ui/win/taskbar_host.h
new file mode 100644
index 000000000000..185b88a6b5b6
--- /dev/null
+++ b/atom/browser/ui/win/taskbar_host.h
@@ -0,0 +1,64 @@
+// Copyright (c) 2015 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_UI_WIN_TASKBAR_HOST_H_
+#define ATOM_BROWSER_UI_WIN_TASKBAR_HOST_H_
+
+#include <shobjidl.h>
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/win/scoped_comptr.h"
+#include "ui/gfx/image/image.h"
+
+namespace atom {
+
+class TaskbarHost {
+ public:
+  struct ThumbarButton {
+    std::string tooltip;
+    gfx::Image icon;
+    std::vector<std::string> flags;
+    base::Closure clicked_callback;
+  };
+
+  TaskbarHost();
+  virtual ~TaskbarHost();
+
+  // Add or update the buttons in thumbar.
+  bool SetThumbarButtons(
+      HWND window, const std::vector<ThumbarButton>& buttons);
+
+  // Set the progress state in taskbar.
+  bool SetProgressBar(HWND window, double value);
+
+  // Set the overlay icon in taskbar.
+  bool SetOverlayIcon(
+      HWND window, const gfx::Image& overlay, const std::string& text);
+
+  // Called by the window that there is a button in thumbar clicked.
+  bool HandleThumbarButtonEvent(int button_id);
+
+ private:
+  // Initailize the taskbar object.
+  bool InitailizeTaskbar();
+
+  using CallbackMap = std::map<int, base::Closure>;
+  CallbackMap callback_map_;
+
+  // The COM object of taskbar.
+  base::win::ScopedComPtr<ITaskbarList3> taskbar_;
+
+  // Whether we have already added the buttons to thumbar.
+  bool thumbar_buttons_added_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskbarHost);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_UI_WIN_TASKBAR_HOST_H_
diff --git a/atom/browser/ui/win/thumbar_host.cc b/atom/browser/ui/win/thumbar_host.cc
deleted file mode 100644
index af57ef4e5c64..000000000000
--- a/atom/browser/ui/win/thumbar_host.cc
+++ /dev/null
@@ -1,141 +0,0 @@
-// Copyright (c) 2015 GitHub, Inc.
-// Use of this source code is governed by the MIT license that can be
-// found in the LICENSE file.
-
-#include "atom/browser/ui/win/thumbar_host.h"
-
-#include <shobjidl.h>
-
-#include <string>
-
-#include "base/win/scoped_comptr.h"
-#include "base/win/win_util.h"
-#include "base/win/wrapped_window_proc.h"
-#include "base/strings/utf_string_conversions.h"
-#include "third_party/skia/include/core/SkBitmap.h"
-#include "ui/gfx/icon_util.h"
-#include "ui/gfx/win/hwnd_util.h"
-
-namespace atom {
-
-namespace {
-
-// From MSDN: https://msdn.microsoft.com/en-us/library/windows/desktop/
-// dd378460(v=vs.85).aspx#thumbbars
-// The thumbnail toolbar has a maximum of seven buttons due to the limited room.
-const int kMaxButtonsCount = 7;
-
-// The base id of Thumbar button.
-const int kButtonIdBase = 40001;
-
-bool GetThumbarButtonFlags(const std::vector<std::string>& flags,
-                           THUMBBUTTONFLAGS* out) {
-  if (flags.empty()) {
-    *out = THBF_ENABLED;
-    return true;
-  }
-  THUMBBUTTONFLAGS result = static_cast<THUMBBUTTONFLAGS>(0);
-  for (const auto& flag : flags) {
-    if (flag == "enabled") {
-      result |= THBF_ENABLED;
-    } else if (flag == "disabled") {
-      result |= THBF_DISABLED;
-    } else if (flag == "dismissonclick") {
-      result |= THBF_DISMISSONCLICK;
-    } else if (flag == "nobackground") {
-      result |= THBF_NOBACKGROUND;
-    } else if (flag == "hidden") {
-      result |= THBF_HIDDEN;
-    } else if (flag == "noninteractive") {
-      result |= THBF_NONINTERACTIVE;
-    } else {
-      return false;
-    }
-  }
-  *out = result;
-  return true;
-}
-
-}  // namespace
-
-ThumbarHost::ThumbarHost(HWND window) : is_initialized_(false),
-                                        window_(window) {
-}
-
-ThumbarHost::~ThumbarHost() {
-}
-
-bool ThumbarHost::SetThumbarButtons(
-    const std::vector<atom::NativeWindow::ThumbarButton>& buttons) {
-  if (buttons.size() > kMaxButtonsCount)
-    return false;
-
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  if (FAILED(taskbar.CreateInstance(CLSID_TaskbarList,
-                                    nullptr,
-                                    CLSCTX_INPROC_SERVER)) ||
-      FAILED(taskbar->HrInit())) {
-    return false;
-  }
-
-  THUMBBUTTON thumb_buttons[kMaxButtonsCount] = {};
-  thumbar_button_clicked_callback_map_.clear();
-
-  // Once a toolbar with a set of buttons is added to thumbnail, there is no way
-  // to remove it without re-creating the window.
-  // To achieve to re-set thumbar buttons,  we initialize the buttons with
-  // HIDDEN state and only updated the caller's specified buttons.
-  //
-  // Initialize all thumb buttons with HIDDEN state.
-  for (int i = 0; i < kMaxButtonsCount; ++i) {
-    thumb_buttons[i].iId = kButtonIdBase + i;
-    thumb_buttons[i].dwMask = THB_FLAGS;  // dwFlags is valid.
-    thumb_buttons[i].dwFlags = THBF_HIDDEN;
-  }
-
-  // Update the callers' specified buttons.
-  for (size_t i = 0; i < buttons.size(); ++i) {
-    if (!GetThumbarButtonFlags(buttons[i].flags, &thumb_buttons[i].dwFlags))
-      return false;
-    thumb_buttons[i].dwMask = THB_ICON | THB_FLAGS;
-    thumb_buttons[i].hIcon = IconUtil::CreateHICONFromSkBitmap(
-        buttons[i].icon.AsBitmap());
-    if (!buttons[i].tooltip.empty()) {
-      thumb_buttons[i].dwMask |= THB_TOOLTIP;
-      wcscpy_s(thumb_buttons[i].szTip,
-               base::UTF8ToUTF16(buttons[i].tooltip).c_str());
-    }
-
-    thumbar_button_clicked_callback_map_[thumb_buttons[i].iId] =
-        buttons[i].clicked_callback;
-  }
-
-  bool is_success = false;
-  if (!is_initialized_) {
-    is_initialized_ = true;
-    is_success = taskbar->ThumbBarAddButtons(
-        window_, buttons.size(), thumb_buttons) == S_OK;
-  } else {
-    is_success = taskbar->ThumbBarUpdateButtons(
-        window_, kMaxButtonsCount, thumb_buttons) == S_OK;
-  }
-
-  // Release thumb_buttons' icons, the taskbar makes its own copy.
-  for (size_t i = 0; i < buttons.size(); ++i) {
-    ::DestroyIcon(thumb_buttons[i].hIcon);
-  }
-  return is_success;
-}
-
-bool ThumbarHost::HandleThumbarButtonEvent(int button_id) {
-  if (thumbar_button_clicked_callback_map_.find(button_id) !=
-      thumbar_button_clicked_callback_map_.end()) {
-    auto callback = thumbar_button_clicked_callback_map_[button_id];
-    if (!callback.is_null())
-      callback.Run();
-    return true;
-  }
-  return false;
-}
-
-}  // namespace atom
diff --git a/atom/browser/ui/win/thumbar_host.h b/atom/browser/ui/win/thumbar_host.h
deleted file mode 100644
index d14bbaeda305..000000000000
--- a/atom/browser/ui/win/thumbar_host.h
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright (c) 2015 GitHub, Inc.
-// Use of this source code is governed by the MIT license that can be
-// found in the LICENSE file.
-
-#ifndef ATOM_BROWSER_UI_WIN_THUMBAR_HOST_H_
-#define ATOM_BROWSER_UI_WIN_THUMBAR_HOST_H_
-
-#include <windows.h>
-
-#include <map>
-#include <vector>
-
-#include "atom/browser/native_window.h"
-
-namespace atom {
-
-class ThumbarHost {
- public:
-  explicit ThumbarHost(HWND window);
-  ~ThumbarHost();
-
-  bool SetThumbarButtons(
-      const std::vector<NativeWindow::ThumbarButton>& buttons);
-  bool HandleThumbarButtonEvent(int button_id);
-
- private:
-  using ThumbarButtonClickedCallbackMap = std::map<
-      int, NativeWindow::ThumbarButtonClickedCallback>;
-  ThumbarButtonClickedCallbackMap thumbar_button_clicked_callback_map_;
-
-  bool is_initialized_;
-
-  HWND window_;
-
-  DISALLOW_COPY_AND_ASSIGN(ThumbarHost);
-};
-
-}  // namespace atom
-
-#endif  // ATOM_BROWSER_UI_WIN_THUMBAR_HOST_H_
diff --git a/docs/api/browser-window.md b/docs/api/browser-window.md
index 60b9b84735d0..612b3ce4f3f0 100644
--- a/docs/api/browser-window.md
+++ b/docs/api/browser-window.md
@@ -646,23 +646,24 @@ __Note:__ This API is only available on Windows (Windows 7 and above)
 
 ### BrowserWindow.setThumbarButtons(buttons)
 
-* `buttons` Array of `button` objects
+* `buttons` Array
   * `button` Object
     * `icon` [NativeImage](native-image.md) - The icon showing in thumbnail
       toolbar.
-    * `tooltip` String - (Option) - The text of the button's tooltip.
-    * `flags` Array of Strings - (Option) Control specific states and behaviors
-      of the button. By default, it uses `enabled`.
-      *  `enabled` - The button is active and available to the user.
-      *  `disabled` - The button is disabled. It is present, but has a visual
-         state that indicates that it will not respond to user action.
-      *  `dismissonclick` - When the button is clicked, the taskbar button's
-         flyout closes immediately.
-      *  `nobackground` - Do not draw a button border, use only the image.
-      *  `hidden` - The button is not shown to the user.
-      *  `noninteractive` - The button is enabled but not interactive; no
-         pressed button state is drawn. This value is intended for instances
-         where the button is used in a notification.
+    * `tooltip` String (optional) - The text of the button's tooltip.
+    * `flags` Array (optional) - Control specific states and behaviors
+      of the button. By default, it uses `enabled`. It can include following
+      Strings:
+      * `enabled` - The button is active and available to the user.
+      * `disabled` - The button is disabled. It is present, but has a visual
+        state that indicates that it will not respond to user action.
+      * `dismissonclick` - When the button is clicked, the taskbar button's
+        flyout closes immediately.
+      * `nobackground` - Do not draw a button border, use only the image.
+      * `hidden` - The button is not shown to the user.
+      * `noninteractive` - The button is enabled but not interactive; no
+        pressed button state is drawn. This value is intended for instances
+        where the button is used in a notification.
     * `click` - Function
 
 Add a thumbnail toolbar with a specified set of buttons to the thumbnail image
diff --git a/filenames.gypi b/filenames.gypi
index 45aaac7c2778..f7b9fca5e717 100644
--- a/filenames.gypi
+++ b/filenames.gypi
@@ -202,14 +202,16 @@
       'atom/browser/ui/views/submenu_button.h',
       'atom/browser/ui/views/win_frame_view.cc',
       'atom/browser/ui/views/win_frame_view.h',
-      "atom/browser/ui/win/atom_desktop_window_tree_host_win.cc",
-      "atom/browser/ui/win/atom_desktop_window_tree_host_win.h",
+      'atom/browser/ui/win/atom_desktop_window_tree_host_win.cc',
+      'atom/browser/ui/win/atom_desktop_window_tree_host_win.h',
+      'atom/browser/ui/win/message_handler_delegate.cc',
+      'atom/browser/ui/win/message_handler_delegate.h',
       'atom/browser/ui/win/notify_icon_host.cc',
       'atom/browser/ui/win/notify_icon_host.h',
       'atom/browser/ui/win/notify_icon.cc',
       'atom/browser/ui/win/notify_icon.h',
-      'atom/browser/ui/win/thumbar_host.cc',
-      'atom/browser/ui/win/thumbar_host.h',
+      'atom/browser/ui/win/taskbar_host.cc',
+      'atom/browser/ui/win/taskbar_host.h',
       'atom/browser/ui/x/window_state_watcher.cc',
       'atom/browser/ui/x/window_state_watcher.h',
       'atom/browser/ui/x/x_window_utils.cc',