Add a bit to not bubble scrolls to parent scrolling layers

cc/layer_tree_host_impl.h

 // 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.
 
 #ifndef CC_LAYER_TREE_HOST_IMPL_H_
 #define CC_LAYER_TREE_HOST_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
@@ skipping 309 matching lines @@
     scoped_ptr<LayerTreeImpl> m_activeTree;
 
     // In impl-side painting mode, tree with possibly incomplete rasterized
     // content. May be promoted to active by activatePendingTreeIfNeeded().
     scoped_ptr<LayerTreeImpl> m_pendingTree;
 
     // In impl-side painting mode, inert tree with layers that can be recycled
     // by the next sync from the main thread.
     scoped_ptr<LayerTreeImpl> m_recycleTree;
 
+    bool m_didScrollOnce;

[Sami, 2013/01/30 19:28:31]

At the risk of bikeshedding I think this name is a bit obscure. Maybe something
like m_didLockScrollingLayer or m_didFindScrollingLayer?

[jamesr, 2013/01/30 19:32:23]

Or maybe it's time to move the transient scroll properties out to another
struct/class?

[Yusuf, 2013/01/30 21:01:02]

Done.

+    bool m_shouldBubbleScrolls;
     bool m_scrollDeltaIsInViewportSpace;
     LayerTreeSettings m_settings;
     LayerTreeDebugState m_debugState;
     gfx::Size m_layoutViewportSize;
     gfx::Size m_deviceViewportSize;
     float m_deviceScaleFactor;
     bool m_visible;
     ManagedMemoryPolicy m_managedMemoryPolicy;
 
     bool m_pinchGestureActive;
@@ skipping 24 matching lines @@
     size_t m_lastSentMemoryUseBytes;
 
     scoped_ptr<AnimationRegistrar> m_animationRegistrar;
 
     DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYER_TREE_HOST_IMPL_H_