cc: Move SyncedScrollOffset to scroll tree

cc/layers/layer_impl_unittest.cc

Index: cc/layers/layer_impl_unittest.cc
diff --git a/cc/layers/layer_impl_unittest.cc b/cc/layers/layer_impl_unittest.cc
index ff553afb7245dd56adaf0cdbff6c4b1f6dd451d3..2146eba72f0377b88d36ef0dcd5defdaeb112758 100644
--- a/cc/layers/layer_impl_unittest.cc
+++ b/cc/layers/layer_impl_unittest.cc
@@ -558,7 +558,7 @@ TEST_F(LayerImplScrollTest, ApplySentScrollsNoListener) {
 
   layer()->PushScrollOffsetFromMainThread(scroll_offset);
   layer()->ScrollBy(sent_scroll_delta);
-  layer()->PullDeltaForMainThread();
+  layer()->synced_scroll_offset()->PullDeltaForMainThread();
   layer()->SetCurrentScrollOffset(scroll_offset +
                                   gfx::ScrollOffset(scroll_delta));
 
@@ -567,7 +567,7 @@ TEST_F(LayerImplScrollTest, ApplySentScrollsNoListener) {
   EXPECT_VECTOR_EQ(scroll_delta, layer()->ScrollDelta());
   EXPECT_VECTOR_EQ(scroll_offset, layer()->BaseScrollOffset());
 
-  layer()->ApplySentScrollDeltasFromAbortedCommit();
+  layer()->synced_scroll_offset()->AbortCommit();
 
   EXPECT_VECTOR_EQ(gfx::ScrollOffsetWithDelta(scroll_offset, scroll_delta),
                    layer()->CurrentScrollOffset());
@@ -600,7 +600,7 @@ TEST_F(LayerImplScrollTest, PushPropertiesToMirrorsCurrentScrollOffset) {
   EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), unscrolled);
   EXPECT_VECTOR_EQ(gfx::Vector2dF(22, 23), layer()->CurrentScrollOffset());
 
-  layer()->PullDeltaForMainThread();
+  layer()->synced_scroll_offset()->PullDeltaForMainThread();
 
   scoped_ptr<LayerImpl> pending_layer = LayerImpl::Create(
       host_impl().sync_tree(), layer()->id(), layer()->synced_scroll_offset());