cc: Change TileManager iterators to be queues.

cc/layers/picture_layer_impl.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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 28 matching lines @@
 // Don't pre-rasterize on the GPU (except for kBackflingGuardDistancePixels in
 // TileManager::BinFromTilePriority).
 const float kGpuSkewportTargetTimeInFrames = 0.0f;
 
 // Minimum width/height of a layer that would require analysis for tiles.
 const int kMinDimensionsForAnalysis = 256;
 }  // namespace
 
 namespace cc {
 
+PairedPictureLayer::PairedPictureLayer()
+    : active_layer(NULL), pending_layer(NULL) {
+}
+
+PairedPictureLayer::~PairedPictureLayer() {
+}
+
 PictureLayerImpl::PictureLayerImpl(LayerTreeImpl* tree_impl, int id)
     : LayerImpl(tree_impl, id),
       twin_layer_(NULL),
       pile_(PicturePileImpl::Create()),
       is_mask_(false),
       ideal_page_scale_(0.f),
       ideal_device_scale_(0.f),
       ideal_source_scale_(0.f),
       ideal_contents_scale_(0.f),
       raster_page_scale_(0.f),
@@ skipping 1576 matching lines @@
   return iterator_index_ < iterators_.size();
 }
 
 bool PictureLayerImpl::LayerEvictionTileIterator::IsCorrectType(
     PictureLayerTiling::TilingEvictionTileIterator* it) const {
   return it->get_type() == iteration_stage_ &&
          (**it)->required_for_activation() == required_for_activation_;
 }
 
 }  // namespace cc