Convert scroll offsets to use SyncedProperty.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 36c63c4fe2f181ffcb5d6005540650b300bd3bbd..15059ba7d2782771774f19bdb197a90c43b34656 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -65,10 +65,12 @@ PictureLayerImpl::Pair::Pair(PictureLayerImpl* active_layer,
 PictureLayerImpl::Pair::~Pair() {
 }
 
-PictureLayerImpl::PictureLayerImpl(LayerTreeImpl* tree_impl,
-                                   int id,
-                                   bool is_mask)
-    : LayerImpl(tree_impl, id),
+PictureLayerImpl::PictureLayerImpl(
+    LayerTreeImpl* tree_impl,
+    int id,
+    bool is_mask,
+    scoped_refptr<SyncedScrollOffset> scroll_offset)
+    : LayerImpl(tree_impl, id, scroll_offset),
       twin_layer_(nullptr),
       tilings_(CreatePictureLayerTilingSet()),
       ideal_page_scale_(0.f),
@@ -100,7 +102,8 @@ const char* PictureLayerImpl::LayerTypeAsString() const {
 
 scoped_ptr<LayerImpl> PictureLayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
-  return PictureLayerImpl::Create(tree_impl, id(), is_mask_);
+  return PictureLayerImpl::Create(tree_impl, id(), is_mask_,
+                                  synced_scroll_offset());
 }
 
 void PictureLayerImpl::PushPropertiesTo(LayerImpl* base_layer) {