Fix UpdateTilePriorities viewport in Android WebView.

cc/test/pixel_test_output_surface.h

 // Copyright 2013 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 CC_TEST_PIXEL_TEST_OUTPUT_SURFACE_H_
 #define CC_TEST_PIXEL_TEST_OUTPUT_SURFACE_H_
 
 #include "cc/output/output_surface.h"
 
 namespace cc {
 
 class PixelTestOutputSurface : public OutputSurface {
  public:
   explicit PixelTestOutputSurface(
       scoped_refptr<ContextProvider> context_provider)
       : OutputSurface(context_provider) {}
   explicit PixelTestOutputSurface(
       scoped_ptr<cc::SoftwareOutputDevice> software_device)
       : OutputSurface(software_device.Pass()) {}
 
   virtual void Reshape(gfx::Size size, float scale_factor) OVERRIDE;
 
   void set_surface_expansion_size(gfx::Size surface_expansion_size) {
     surface_expansion_size_ = surface_expansion_size;
   }
   void set_viewport_offset(gfx::Vector2d viewport_offset) {
     viewport_offset_ = viewport_offset;
   }
+  void set_device_clip(gfx::Rect device_clip) {
+    device_clip_ = device_clip;
+  }
 
  private:
   gfx::Size surface_expansion_size_;
   gfx::Vector2d viewport_offset_;
+  gfx::Rect device_clip_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_PIXEL_TEST_OUTPUT_SURFACE_H_