From 2067d5a31905f889d7537c4a4ab680577bb5e75f Mon Sep 17 00:00:00 2001
From: Heilig Benedek <benecene@gmail.com>
Date: Thu, 20 Sep 2018 17:47:54 -0700
Subject: disable-redraw-lock.patch

Chromium uses a custom window titlebar implementation on Windows when DWM
is disabled (Windows 7 and earlier, non Aero theme). The native titlebar
sometimes painted over this custom titlebar, so a workaround was put in
place to lock redraws in reaction to certain events if DWM is disabled,
since the code assumes that in that case, the custom titlebar is painted.
Electron forces the use of the native titlebar, which the workaround doesn't
take into account, and still locks redraws, causing weird repainting issues
in electron (and other applications). This patch provides a way to disable
the redraw locking mechanism, which fixes these issues. The electron issue
can be found at https://github.com/electron/electron/issues/1821

diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index d5f442f71da7..a8f39b060115 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -281,6 +281,10 @@ const int kSynthesizedMouseMessagesTimeDifference = 500;
 
 }  // namespace
 
+bool HWNDMessageHandlerDelegate::HasNativeFrame() const {
+  return false;
+}
+
 // A scoping class that prevents a window from being able to redraw in response
 // to invalidations that may occur within it for the lifetime of the object.
 //
@@ -332,6 +336,7 @@ class HWNDMessageHandler::ScopedRedrawLock {
         cancel_unlock_(false),
         should_lock_(owner_->IsVisible() && !owner->HasChildRenderingWindow() &&
                      ::IsWindow(hwnd_) &&
+                     !owner_->HasNativeFrame() &&
                      (!(GetWindowLong(hwnd_, GWL_STYLE) & WS_CAPTION) ||
                       !ui::win::IsAeroGlassEnabled())) {
     if (should_lock_)
@@ -940,6 +945,10 @@ bool HWNDMessageHandler::HasChildRenderingWindow() {
       hwnd());
 }
 
+bool HWNDMessageHandler::HasNativeFrame() {
+  return delegate_->HasNativeFrame();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // HWNDMessageHandler, gfx::WindowImpl overrides:
 
diff --git a/ui/views/win/hwnd_message_handler.h b/ui/views/win/hwnd_message_handler.h
index 91afedec8e29..fa514d102538 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -181,6 +181,8 @@ class VIEWS_EXPORT HWNDMessageHandler : public gfx::WindowImpl,
   typedef std::set<DWORD> TouchIDs;
   enum class DwmFrameState { OFF, ON };
 
+  bool HasNativeFrame();
+
   // Overridden from WindowImpl:
   HICON GetDefaultWindowIcon() const override;
   HICON GetSmallWindowIcon() const override;
diff --git a/ui/views/win/hwnd_message_handler_delegate.h b/ui/views/win/hwnd_message_handler_delegate.h
index 1b2d98a85738..dd080180aebd 100644
--- a/ui/views/win/hwnd_message_handler_delegate.h
+++ b/ui/views/win/hwnd_message_handler_delegate.h
@@ -46,6 +46,8 @@ class VIEWS_EXPORT HWNDMessageHandlerDelegate {
   // True if the widget associated with this window has a non-client view.
   virtual bool HasNonClientView() const = 0;
 
+  virtual bool HasNativeFrame() const;
+
   // Returns who we want to be drawing the frame. Either the system (Windows)
   // will handle it or Chrome will custom draw it.
   virtual FrameMode GetFrameMode() const = 0;
-- 
2.17.0