cc: Damage layer on delegated scroll

cc/trees/layer_tree_impl.cc

 // Copyright 2011 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/trees/layer_tree_impl.h"
 
 #include <limits>
 #include <set>
 
 #include "base/debug/trace_event.h"
@@ skipping 910 matching lines @@
       outer_viewport_scroll_delegate_proxy_ = make_scoped_ptr(
           new LayerScrollOffsetDelegateProxy(OuterViewportScrollLayer(),
                                              root_layer_scroll_offset_delegate_,
                                              this));
       outer_viewport_scroll_layer_->SetScrollOffsetDelegate(
           outer_viewport_scroll_delegate_proxy_.get());
     }
   }
 }
 
+void LayerTreeImpl::OnRootLayerDelegatedScrollOffsetChanged() {
+  DCHECK(root_layer_scroll_offset_delegate_);
+  if (inner_viewport_scroll_layer_) {
+    inner_viewport_scroll_layer_->DidScroll();
+  }
+  if (outer_viewport_scroll_layer_) {
+    outer_viewport_scroll_layer_->DidScroll();
+  }
+}
+
 void LayerTreeImpl::UpdateScrollOffsetDelegate() {
   DCHECK(InnerViewportScrollLayer());
   DCHECK(root_layer_scroll_offset_delegate_);
 
   gfx::ScrollOffset offset =
       inner_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 
   if (OuterViewportScrollLayer())
     offset += outer_viewport_scroll_delegate_proxy_->last_set_scroll_offset();
 
@@ skipping 559 matching lines @@
                                   page_scale,
                                   duration.InSecondsF());
   }
 }
 
 scoped_ptr<PageScaleAnimation> LayerTreeImpl::TakePageScaleAnimation() {
   return page_scale_animation_.Pass();
 }
 
 }  // namespace cc