Ensure Surface size always matches window size on swap

ui/compositor/compositor.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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 238 matching lines @@
 }
 
 void Compositor::ScheduleFullRedraw() {
   host_->SetNeedsRedraw();
 }
 
 void Compositor::ScheduleRedrawRect(const gfx::Rect& damage_rect) {
   host_->SetNeedsRedrawRect(damage_rect);
 }
 
-void Compositor::FinishAllRendering() {
+void Compositor::DisableSwapUntilResize() {
   host_->FinishAllRendering();
+  context_factory_->ResizeDisplay(this, gfx::Size());
 }
 
 void Compositor::SetLatencyInfo(const ui::LatencyInfo& latency_info) {
   scoped_ptr<cc::SwapPromise> swap_promise(
       new cc::LatencyInfoSwapPromise(latency_info));
   host_->QueueSwapPromise(swap_promise.Pass());
 }
 
 void Compositor::SetScaleAndSize(float scale, const gfx::Size& size_in_pixel) {
   DCHECK_GT(scale, 0);
   if (!size_in_pixel.IsEmpty()) {
     size_ = size_in_pixel;
     host_->SetViewportSize(size_in_pixel);
     root_web_layer_->SetBounds(size_in_pixel);
+    context_factory_->ResizeDisplay(this, size_in_pixel);
   }
   if (device_scale_factor_ != scale) {
     device_scale_factor_ = scale;
     host_->SetDeviceScaleFactor(scale);
     if (root_layer_)
       root_layer_->OnDeviceScaleFactorChanged(scale);
   }
 }
 
 void Compositor::SetBackgroundColor(SkColor color) {
@@ skipping 175 matching lines @@
     // Call ScheduleDraw() instead of Draw() in order to allow other
     // CompositorObservers to be notified before starting another
     // draw cycle.
     ScheduleDraw();
   }
   FOR_EACH_OBSERVER(
       CompositorObserver, observer_list_, OnCompositingEnded(this));
 }
 
 }  // namespace ui