cc: Add CopyAsBitmapRequest class to hold the readback callback.

cc/trees/layer_tree_host_common.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_host_common.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/base/math_util.h"
@@ skipping 358 matching lines @@
   //
   // These are allowed on the root surface, as they don't require the surface to
   // be used as a contributing surface in order to apply correctly.
   //
 
   // If we force it.
   if (layer->force_render_surface())
     return true;
 
   // If we'll make a copy of the layer's contents.
-  if (layer->HasRequestCopyCallback())
+  if (layer->HasCopyRequest())
     return true;
 
   return false;
 }
 
 static LayerImpl* NextTargetSurface(LayerImpl* layer) {
   return layer->parent() ? layer->parent()->render_target() : 0;
 }
 
 // This function returns a translation matrix that can be applied on a vector
@@ skipping 1431 matching lines @@
   // At this point, we think the point does hit the touch event handler region
   // on the layer, but we need to walk up the parents to ensure that the layer
   // was not clipped in such a way that the hit point actually should not hit
   // the layer.
   if (PointIsClippedBySurfaceOrClipRect(screen_space_point, layer_impl))
     return false;
 
   return true;
 }
 }  // namespace cc