cc/blimp: Add synchronization for scroll/scale state.

cc/trees/property_tree.cc

 // Copyright 2014 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 <stddef.h>
 
 #include <set>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 1654 matching lines @@
 
 bool ScrollTree::SetScrollOffset(int layer_id,
                                  const gfx::ScrollOffset& scroll_offset) {
   if (property_trees()->is_main_thread)
     return synced_scroll_offset(layer_id)->PushFromMainThread(scroll_offset);
   else if (property_trees()->is_active)
     return synced_scroll_offset(layer_id)->SetCurrent(scroll_offset);
   return false;
 }
 
+void ScrollTree::AddUnappliedScrollOffsetDeltaToPendingTree(
+    int layer_id,
+    const gfx::ScrollOffset& scroll_offset_delta) {
+  DCHECK(!property_trees()->is_main_thread);
+  DCHECK(!property_trees()->is_active);
+
+  synced_scroll_offset(layer_id)->AddUnappliedDeltaToPendingBase(
+      scroll_offset_delta);
+}
+
 bool ScrollTree::UpdateScrollOffsetBaseForTesting(
     int layer_id,
     const gfx::ScrollOffset& offset) {
   DCHECK(!property_trees()->is_main_thread);
   bool changed = synced_scroll_offset(layer_id)->PushFromMainThread(offset);
   if (property_trees()->is_active)
     changed |= synced_scroll_offset(layer_id)->PushPendingToActive();
   return changed;
 }
 
@@ skipping 683 matching lines @@
 
   const EffectNode* effect_node = effect_tree.Node(effect_id);
 
   bool success = GetFromTarget(transform_id, effect_id, transform);
   transform->Scale(effect_node->surface_contents_scale.x(),
                    effect_node->surface_contents_scale.y());
   return success;
 }
 
 }  // namespace cc