Makes tile-creation lazy

cc/resources/picture_layer_tiling_set.cc

 // 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.
 
 #include "cc/resources/picture_layer_tiling_set.h"
 
 namespace cc {
 
 namespace {
 
@@ skipping 37 matching lines @@
 void PictureLayerTilingSet::Clone(
     const PictureLayerTiling* tiling,
     const Region& invalidation) {
 
   for (size_t i = 0; i < tilings_.size(); ++i)
     DCHECK_NE(tilings_[i]->contents_scale(), tiling->contents_scale());
 
   tilings_.push_back(tiling->Clone());
   gfx::Size size = tilings_.back()->layer_bounds();
   tilings_.back()->SetClient(client_);
-  tilings_.back()->Invalidate(invalidation);

[enne (OOO), 2013/03/27 16:16:27]

I like being able to get rid of this function.  :)

   // Intentionally use this set's layer bounds, as it may have changed.
   tilings_.back()->SetLayerBounds(layer_bounds_);
 
   tilings_.sort(LargestToSmallestScaleFunctor());
 }
 
 void PictureLayerTilingSet::SetLayerBounds(gfx::Size layer_bounds) {
   if (layer_bounds_ == layer_bounds)
     return;
   layer_bounds_ = layer_bounds;
@@ skipping 230 matching lines @@
 }
 
 scoped_ptr<base::Value> PictureLayerTilingSet::AsValue() const {
   scoped_ptr<base::ListValue> state(new base::ListValue());
   for (size_t i = 0; i < tilings_.size(); ++i)
     state->Append(tilings_[i]->AsValue().release());
   return state.PassAs<base::Value>();
 }
 
 }  // namespace cc