diff --git a/browser/native_window.cc b/browser/native_window.cc
index b3bb5efc5d0c..c656edbf6667 100644
--- a/browser/native_window.cc
+++ b/browser/native_window.cc
@@ -45,6 +45,7 @@ NativeWindow::NativeWindow(content::WebContents* web_contents,
       has_frame_(true),
       is_closed_(false),
       not_responding_(false),
+      weak_factory_(this),
       inspectable_web_contents_(
           brightray::InspectableWebContents::Create(web_contents)) {
   options->GetBoolean(switches::kFrame, &has_frame_);
@@ -205,7 +206,7 @@ void NativeWindow::CapturePage(const gfx::Rect& rect,
       rect,
       gfx::Size(),
       base::Bind(&NativeWindow::OnCapturePageDone,
-                 base::Unretained(this),
+                 weak_factory_.GetWeakPtr(),
                  callback));
 }
 
@@ -221,6 +222,12 @@ void NativeWindow::CloseWebContents() {
 
   content::WebContents* web_contents(GetWebContents());
 
+  // Assume the window is not responding if it doesn't cancel the close and is
+  // not closed in 500ms, in this way we can quickly show the unresponsive
+  // dialog when the window is busy executing some script withouth waiting for
+  // the unresponsive timeout.
+  RendererUnresponsive(web_contents);
+
   if (web_contents->NeedToFireBeforeUnload())
     web_contents->GetRenderViewHost()->FirePageBeforeUnload(false);
   else
@@ -277,6 +284,9 @@ void NativeWindow::BeforeUnloadFired(content::WebContents* tab,
 
   if (!proceed)
     WindowList::WindowCloseCancelled(this);
+
+  // When the "beforeunload" callback is fired the window is certainly live.
+  not_responding_ = false;
 }
 
 void NativeWindow::RequestToLockMouse(content::WebContents* web_contents,
@@ -319,6 +329,9 @@ void NativeWindow::CloseContents(content::WebContents* source) {
   CloseImmediately();
 
   NotifyWindowClosed();
+
+  // Do not sent "unresponsive" event after window is closed.
+  not_responding_ = false;
 }
 
 bool NativeWindow::IsPopupOrPanel(const content::WebContents* source) const {
@@ -331,8 +344,8 @@ void NativeWindow::RendererUnresponsive(content::WebContents* source) {
   base::MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&NativeWindow::RendererUnresponsiveDelayed,
-                 base::Unretained(this)),
-      base::TimeDelta::FromSeconds(1));
+                 weak_factory_.GetWeakPtr()),
+      base::TimeDelta::FromMilliseconds(500));
 }
 
 void NativeWindow::RendererResponsive(content::WebContents* source) {
diff --git a/browser/native_window.h b/browser/native_window.h
index 2506afb55071..316f6f5fe18e 100644
--- a/browser/native_window.h
+++ b/browser/native_window.h
@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "browser/native_window_observer.h"
 #include "content/public/browser/notification_registrar.h"
@@ -216,6 +217,8 @@ class NativeWindow : public brightray::DefaultWebContentsDelegate,
   // The window is not responding.
   bool not_responding_;
 
+  base::WeakPtrFactory<NativeWindow> weak_factory_;
+
   scoped_ptr<AtomJavaScriptDialogManager> dialog_manager_;
   scoped_ptr<brightray::InspectableWebContents> inspectable_web_contents_;