cc: Move SyncedScrollOffset to scroll tree

cc/layers/picture_layer_impl_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <limits>
@@ skipping 221 matching lines @@
     // Steal from the recycled tree if possible.
     scoped_ptr<LayerImpl> pending_root = pending_tree->DetachLayerTree();
     scoped_ptr<FakePictureLayerImpl> pending_layer;
     DCHECK(!pending_root || pending_root->id() == root_id_);
     if (!pending_root) {
       pending_root = LayerImpl::Create(pending_tree, root_id_);
       pending_layer = FakePictureLayerImpl::Create(pending_tree, id_);
       if (!tile_size.IsEmpty())
         pending_layer->set_fixed_tile_size(tile_size);
       pending_layer->SetDrawsContent(true);
+      pending_layer->SetScrollClipLayer(pending_root->id());
     } else {
       pending_layer.reset(static_cast<FakePictureLayerImpl*>(
           pending_root->RemoveChild(pending_root->children()[0].get())
               .release()));
       if (!tile_size.IsEmpty())
         pending_layer->set_fixed_tile_size(tile_size);
     }
     pending_root->SetForceRenderSurface(true);
     // The bounds() just mirror the raster source size.
     pending_layer->SetBounds(raster_source->GetSize());
@@ skipping 4670 matching lines @@
   // New low res tiling.
   EXPECT_TRUE(tilings->tiling_at(2)->may_contain_low_resolution_tiles());
 
   // This tiling will be high res now, it won't contain low res content since it
   // was all destroyed.
   EXPECT_FALSE(tilings->tiling_at(1)->may_contain_low_resolution_tiles());
 }
 
 }  // namespace
 }  // namespace cc