Re-land: cc: Examine layers to determine if we're ready to activate.

cc/layers/picture_layer_impl.h

 // Copyright 2012 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_LAYERS_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 123 matching lines @@
 
   bool use_gpu_rasterization() const {
     return layer_tree_impl()->use_gpu_rasterization();
   }
 
   // Functions used by tile manager.
   void DidUnregisterLayer();
   PictureLayerImpl* GetTwinLayer() { return twin_layer_; }
   WhichTree GetTree() const;
   bool IsOnActiveOrPendingTree() const;
+  bool AllTilesRequiredForActivationAreReadyToDraw() const;
 
  protected:
   friend class LayerRasterTileIterator;
 
   PictureLayerImpl(LayerTreeImpl* tree_impl, int id);
   PictureLayerTiling* AddTiling(float contents_scale);
   void RemoveTiling(float contents_scale);
   void RemoveAllTilings();
   void SyncFromActiveLayer(const PictureLayerImpl* other);
   void ManageTilings(bool animating_transform_to_screen,
@@ skipping 69 matching lines @@
   gfx::Size viewport_size_for_tile_priority_;
   gfx::Transform screen_space_transform_for_tile_priority_;
 
   friend class PictureLayer;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_