Ensure Surface size always matches window size on swap

ui/compositor/compositor.h

 // 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.
 
 #ifndef UI_COMPOSITOR_COMPOSITOR_H_
 #define UI_COMPOSITOR_COMPOSITOR_H_
 
 #include <string>
 
 #include "base/containers/hash_tables.h"
@@ skipping 87 matching lines @@
 
   // Gets the GPU memory buffer manager.
   virtual gpu::GpuMemoryBufferManager* GetGpuMemoryBufferManager() = 0;
 
   // Gets the compositor message loop, or NULL if not using threaded
   // compositing.
   virtual base::MessageLoopProxy* GetCompositorMessageLoop() = 0;
 
   // Creates a Surface ID allocator with a new namespace.
   virtual scoped_ptr<cc::SurfaceIdAllocator> CreateSurfaceIdAllocator() = 0;
+
+  // Resize the display corresponding to this compositor to a particular size.
+  virtual void ResizeDisplay(ui::Compositor* compositor,
+                             const gfx::Size& size) = 0;
 };
 
 // This class represents a lock on the compositor, that can be used to prevent
 // commits to the compositor tree while we're waiting for an asynchronous
 // event. The typical use case is when waiting for a renderer to produce a frame
 // at the right size. The caller keeps a reference on this object, and drops the
 // reference once it desires to release the lock.
 // Note however that the lock is cancelled after a short timeout to ensure
 // responsiveness of the UI, so the compositor tree should be kept in a
 // "reasonable" state while the lock is held.
@@ skipping 58 matching lines @@
 
   // Where possible, draws are scissored to a damage region calculated from
   // changes to layer properties.  This bypasses that and indicates that
   // the whole frame needs to be drawn.
   void ScheduleFullRedraw();
 
   // Schedule redraw and append damage_rect to the damage region calculated
   // from changes to layer properties.
   void ScheduleRedrawRect(const gfx::Rect& damage_rect);
 
-  // Finishes all outstanding rendering on the GPU.
-  void FinishAllRendering();
+  // Disable swapping on this surface until it is resized.

[piman, 2014/12/01 23:42:09]

Nit: "Finishes all outstanding rendering and disable swapping...."

+  void DisableSwapUntilResize();
 
   void SetLatencyInfo(const LatencyInfo& latency_info);
 
   // Sets the compositor's device scale factor and size.
   void SetScaleAndSize(float scale, const gfx::Size& size_in_pixel);
 
   // Returns the size of the widget that is being drawn to in pixel coordinates.
   const gfx::Size& size() const { return size_; }
 
   // Sets the background color used for areas that aren't covered by
@@ skipping 139 matching lines @@
   LayerAnimatorCollection layer_animator_collection_;
 
   base::WeakPtrFactory<Compositor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_