From 0000000000000000000000000000000000000000 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 4c9654191ddce3db5f9391cdbd07b1be8a77a2af..dc2cdf7467912d36261583c91c8f46fbe041c5e0 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -304,6 +304,10 @@ constexpr 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.
 //
@@ -355,6 +359,7 @@ 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_)
@@ -969,6 +974,10 @@ HWNDMessageHandler::RegisterUnadjustedMouseEvent() {
   return scoped_enable;
 }
 
+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 3d498de563ed739f55136f83b110b31bd66a1b5c..5d7810c9e31d9948212826377d6f039ad5761ba6 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -202,6 +202,8 @@ class VIEWS_EXPORT HWNDMessageHandler : public gfx::WindowImpl,
   using TouchIDs = std::set<DWORD>;
   enum class DwmFrameState { kOff, kOn };
 
+  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 7344cdd4cf7d68da617b81cbdf464a859a40fb09..9ec1f23b26b41e10a46be0ca5d254583b6534ecb 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;
