Fix large mis-paint when resizing windows aura chrome

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 753 matching lines @@
   if (window_->bounds().size() != rect.size() &&
       host_->is_accelerated_compositing_active()) {
     aura::RootWindow* root_window = window_->GetRootWindow();
     ui::Compositor* compositor = root_window ?
         root_window->compositor() : NULL;
     if (root_window && compositor) {
       // Listen to changes in the compositor lock state.
       if (!compositor->HasObserver(this))
         compositor->AddObserver(this);
 
+// On Windows while resizing, the the resize locks makes us mis-paint a white
+// vertical strip (including the non-client area) if the content composition is
+// lagging the UI composition. So here we disable the throttling so that the UI
+// bits can draw ahead of the content thereby reducing the amount of whiteout.
+// Because this causes the content to be drawn at wrong sizes while resizing
+// we compensate by blocking the UI thread in Compositor::Draw() by issuing a
+// FinishAllRendering() if we are resizing.
+#if !defined (OS_WIN)
       bool defer_compositor_lock =
          can_lock_compositor_ == NO_PENDING_RENDERER_FRAME ||
          can_lock_compositor_ == NO_PENDING_COMMIT;
 
       if (can_lock_compositor_ == YES)
         can_lock_compositor_ = YES_DID_LOCK;
 
       resize_locks_.push_back(make_linked_ptr(
           new ResizeLock(root_window, rect.size(), defer_compositor_lock)));
+#endif
     }
   }
   window_->SetBounds(rect);
   host_->WasResized();
 }
 
 gfx::NativeView RenderWidgetHostViewAura::GetNativeView() const {
   return window_;
 }
 
@@ skipping 1881 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content