cc: Consider scroll offset in CalcDrawProperties

cc/layers/layer.h

 // Copyright 2010 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_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 224 matching lines @@
 
   void SetDrawCheckerboardForMissingTiles(bool checkerboard);
   bool DrawCheckerboardForMissingTiles() const {
     return draw_checkerboard_for_missing_tiles_;
   }
 
   void SetForceRenderSurface(bool force_render_surface);
   bool force_render_surface() const { return force_render_surface_; }
 
   gfx::Vector2d ScrollDelta() const { return gfx::Vector2d(); }
+  gfx::Vector2dF TotalScrollOffset() const {
+    // Floating point to match the LayerImpl version.
+    return scroll_offset() + ScrollDelta();
+  }
 
   void SetDoubleSided(bool double_sided);
   bool double_sided() const { return double_sided_; }
 
   void SetPreserves3d(bool preserves_3d) { preserves_3d_ = preserves_3d; }
   bool preserves_3d() const { return preserves_3d_; }
 
   void set_use_parent_backface_visibility(bool use) {
     use_parent_backface_visibility_ = use;
   }
@@ skipping 233 matching lines @@
   DrawProperties<Layer, RenderSurface> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_