Make it possible to delegate root layer scroll offset outside of cc.

This change makes it possible for the embedder to own the root layer
scroll offset.

BUG=b/6029133

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=197178

R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/13869006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@197390 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 1 deletions

diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 697676e..d52d6fa 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -284,6 +284,8 @@ class CC_EXPORT LayerImpl : LayerAnimationValueObserver {
                                       float* contents_scale_y,
                                       gfx::Size* content_bounds);
 
+  void SetScrollOffsetDelegate(
+      LayerScrollOffsetDelegate* scroll_offset_delegate);
   void SetScrollOffset(gfx::Vector2d scroll_offset);
   gfx::Vector2d scroll_offset() const { return scroll_offset_; }
 
@@ -291,7 +293,7 @@ class CC_EXPORT LayerImpl : LayerAnimationValueObserver {
   gfx::Vector2d max_scroll_offset() const { return max_scroll_offset_; }
 
   void SetScrollDelta(gfx::Vector2dF scroll_delta);
-  gfx::Vector2dF scroll_delta() const { return scroll_delta_; }
+  gfx::Vector2dF ScrollDelta() const;
 
   gfx::Vector2dF TotalScrollOffset() const;
 
@@ -456,6 +458,7 @@ class CC_EXPORT LayerImpl : LayerAnimationValueObserver {
   float anchor_point_z_;
   gfx::Size bounds_;
   gfx::Vector2d scroll_offset_;
+  LayerScrollOffsetDelegate* scroll_offset_delegate_;
   bool scrollable_;
   bool should_scroll_on_main_thread_;
   bool have_wheel_event_handlers_;