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..c8aad93d67fce610d81d9051ca3a96ab52f17e43 100644
--- a/cc/layers/layer_impl_unittest.cc
+++ b/cc/layers/layer_impl_unittest.cc
@@ -329,8 +329,7 @@ TEST(LayerImplTest, VerifyNeedsUpdateDrawProperties) {
       layer->SetScrollDelta(arbitrary_vector2d));
   VERIFY_NEEDS_UPDATE_DRAW_PROPERTIES(layer->PushScrollOffsetFromMainThread(
       gfx::ScrollOffset(arbitrary_vector2d)));
-  VERIFY_NO_NEEDS_UPDATE_DRAW_PROPERTIES(layer->PushScrollOffsetFromMainThread(
-      gfx::ScrollOffset(arbitrary_vector2d)));
+  VERIFY_NEEDS_UPDATE_DRAW_PROPERTIES(layer->DidUpdateScrollOffset());

[sunxd, 2016/03/03 16:01:25]

This is the change in the test. It seems to me that we can probably remove this
line since DidUpdateScrollOffset is called in the previous line?

[ajuma, 2016/03/03 18:05:06]

The previous line is testing LayerImpl::PushScrollOFfsetFromMainThread, which is
now only called in tests, right? Even though this happens to lead to
LayerImpl::DidUpdateScrollOffset, a test that calls DidUpdateScrollOffset
directly seems worth having.

[sunxd, 2016/03/03 18:50:12]

Done.

 
   // Unrelated functions, always set to new values, always set needs update.
   VERIFY_NEEDS_UPDATE_DRAW_PROPERTIES(
@@ -558,7 +557,7 @@ 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 +566,7 @@ 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());
@@ -600,10 +599,10 @@ 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());
+  scoped_ptr<LayerImpl> pending_layer =
+      LayerImpl::Create(host_impl().sync_tree(), layer()->id());
   pending_layer->PushScrollOffsetFromMainThread(layer()->CurrentScrollOffset());
 
   pending_layer->PushPropertiesTo(layer());