(not for review) Add overhang resource

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 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_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <string>
 #include <vector>
@@ skipping 251 matching lines @@
   ManagedMemoryPolicy ActualManagedMemoryPolicy() const;
 
   size_t memory_allocation_limit_bytes() const;
 
   void SetViewportSize(gfx::Size device_viewport_size);
   gfx::Size device_viewport_size() const { return device_viewport_size_; }
 
   void SetOverdrawBottomHeight(float overdraw_bottom_height);
   float overdraw_bottom_height() const { return overdraw_bottom_height_; }
 
+  void SetOverhangUIResource(UIResourceId overhang_ui_resource_id,
+                             gfx::Size overhang_image_size);
+
   void SetDeviceScaleFactor(float device_scale_factor);
   float device_scale_factor() const { return device_scale_factor_; }
 
   const gfx::Transform& DeviceTransform() const;
 
   scoped_ptr<ScrollAndScaleSet> ProcessScrollDeltas();
 
   bool needs_animate_layers() const {
     return !animation_registrar_->active_animation_controllers().empty();
   }
@@ skipping 245 matching lines @@
   // Conversion factor from CSS pixels to physical pixels when
   // pageScaleFactor=1.
   float device_scale_factor_;
 
   // Vertical amount of the viewport size that's known to covered by a
   // browser-side UI element, such as an on-screen-keyboard.  This affects
   // scrollable size since we want to still be able to scroll to the bottom of
   // the page when the keyboard is up.
   float overdraw_bottom_height_;
 
+  UIResourceId overhang_ui_resource_id_;
+  gfx::Size overhang_image_size_;
+
   // Optional top-level constraints that can be set by the OutputSurface.  The
   // external_viewport_'s size takes precedence over device_viewport_size_ for
   // DrawQuad generation and Renderer; however, device_viewport_size_ is still
   // used for scrollable size.
   gfx::Transform external_transform_;
   gfx::Rect external_viewport_;
   bool external_stencil_test_enabled_;
 
   gfx::Rect viewport_damage_rect_;
 
   base::TimeTicks current_frame_timeticks_;
   base::Time current_frame_time_;
 
   scoped_ptr<AnimationRegistrar> animation_registrar_;
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
 
   bool need_to_update_visible_tiles_before_draw_;
 
   // Optional callback to notify of new tree activations.
   base::Closure tree_activation_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_