Revert 204442 "Split Layer::SetScrollOffset to two functions for..."

webkit_unit_tests gets broken after 20442.
Logs:
 http://build.chromium.org/p/chromium.linux/builders/Android%20Tests%20%28dbg%29/builds/11442
 http://build.chromium.org/p/chromium.linux/builders/Android%20Tests/builds/4910

> Split Layer::SetScrollOffset to two functions for different use
> 
> Currently there are two callers to Layer::SetScrollOffset. One is from
> the Blink ScrollingCoordinator to setup scrolling parameters. The other
> one is from the threaded compositing commits to apply scroll deltas.
> 
> After the patch we have Layer::SetScrollOffset for Blink. This version
> will setNeedsCommit(), but will not notify ScrollableArea (who initiated
> the scroll anyway) for the change. And a new function
> Layer::SetScrollOffsetFromImplSide for commits. This version will notify
> ScrollableArea about the change, but won't setNeedsCommit() for no reason.
> 
> This fixes a use-after-free bug in Layer::SetScrollOffset, due to
> ScrollableArea destroying the layer during the process then the layer
> attempts to setNeedsCommit().
> 
> R=jamesr@chromium.org
> BUG=245713,245987
> NOTRY=true
> TEST=cc_unittests:LayerTreeHostScrollTestLayerStructureChange.*
> 
> Review URL: https://chromiumcodereview.appspot.com/15984005

TBR=trchen@chromium.org

Review URL: https://codereview.chromium.org/16460005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204461 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 11 deletions

diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index 5ec0621..09e1a46 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -515,19 +515,9 @@ void Layer::SetScrollOffset(gfx::Vector2d scroll_offset) {
   if (scroll_offset_ == scroll_offset)
     return;
   scroll_offset_ = scroll_offset;
-  SetNeedsCommit();
-}
-
-void Layer::SetScrollOffsetFromImplSide(gfx::Vector2d scroll_offset) {
-  DCHECK(IsPropertyChangeAllowed());
-  DCHECK(layer_tree_host_ && layer_tree_host_->CommitRequested());
-  if (scroll_offset_ == scroll_offset)
-    return;
-  scroll_offset_ = scroll_offset;
   if (layer_scroll_client_)
     layer_scroll_client_->didScroll();
-  // Note: didScroll() could potentially change the layer structure.
-  //       "this" may have been destroyed during the process.
+  SetNeedsCommit();
 }
 
 void Layer::SetMaxScrollOffset(gfx::Vector2d max_scroll_offset) {