Made Blink aware of top controls offset (Chromium-side)

cc/trees/layer_tree_host_common.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_COMMON_H_
 #define CC_TREES_LAYER_TREE_HOST_COMMON_H_
 
 #include <limits>
 #include <vector>
 
@@ skipping 122 matching lines @@
     gfx::Vector2d scroll_delta;
   };
 };
 
 struct CC_EXPORT ScrollAndScaleSet {
   ScrollAndScaleSet();
   ~ScrollAndScaleSet();
 
   std::vector<LayerTreeHostCommon::ScrollUpdateInfo> scrolls;
   float page_scale_delta;
+  int top_controls_content_offset;

[aelias_OOO_until_Jul13, 2014/08/29 04:37:01]

scrolls and page scale updates in this struct are deltas, can this one be as
well for consistency?

[bokan, 2014/08/29 18:02:14]

Yup, though I think the value that gets sent to Blink will should still be
offset+delta (for the reason mentioned in my comment in render_widget)

[bokan, 2014/09/02 18:57:16]

Just realized doing this has the same problem with RenderWidget::Resize causing
a double application of the sent delta, I'll wait until we clear that up.

   ScopedPtrVector<SwapPromise> swap_promises;
 };
 
 template <typename LayerType>
 bool LayerTreeHostCommon::RenderSurfaceContributesToTarget(
     LayerType* layer,
     int target_surface_layer_id) {
   // A layer will either contribute its own content, or its render surface's
   // content, to the target surface. The layer contributes its surface's content
   // when both the following are true:
@@ skipping 94 matching lines @@
           false,
           render_surface_layer_list,
           0) {
   DCHECK(root_layer);
   DCHECK(render_surface_layer_list);
 }
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_COMMON_H_