Update InnerViewportContainerLayer size when top controls move.

At present, when Clank's top controls move, the InnerViewportContainerLayer
size is not updated immediately, leading to incorrect results from
LayerImpl::MaxScrollOffset() until the resize occurs. This allows scrolling
past the end of the page in the case where the top-controls are hidden
during a single scroll that reaches the bottom of the document.

This CL updates the InnerViewportContainerLayer size on the impl thread
each time the top controls move in order to eliminate this problem. The
mechanism for computing scrollbar vertical adjust has also been updated
to account for this.

Also, this CL makes the previous FixedPositionContainerSizeDelta
computation redundant, and it has been removed.

BUG=342857

Review URL: https://codereview.chromium.org/171813008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253743 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 3 deletions

diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 9815c13..3da5dae 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -123,7 +123,7 @@ class CC_EXPORT LayerTreeImpl {
   gfx::Vector2dF TotalMaxScrollOffset() const;
   gfx::Vector2dF TotalScrollDelta() const;
 
-  LayerImpl* RootContainerLayer() const;
+  LayerImpl* InnerViewportContainerLayer() const;
   LayerImpl* CurrentlyScrollingLayer() const;
   void SetCurrentlyScrollingLayer(LayerImpl* layer);
   void ClearCurrentlyScrollingLayer();
@@ -246,8 +246,6 @@ class CC_EXPORT LayerTreeImpl {
  protected:
   explicit LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
 
-  void UpdateRootScrollLayerSizeDelta();
-
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;