cc: Change TileManager iterators to be queues.

cc/trees/layer_tree_host_impl_unittest.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_impl.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 6681 matching lines @@
   float y = scrolling_layer->TotalScrollOffset().y();
   EXPECT_TRUE(y > 1 && y < 49);
 
   host_impl_->Animate(start_time + base::TimeDelta::FromMilliseconds(200));
   host_impl_->UpdateAnimationState(true);
 
   EXPECT_EQ(gfx::Vector2dF(0, 50), scrolling_layer->TotalScrollOffset());
   EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
 }
 
+TEST_F(LayerTreeHostImplTest, PairedPictureLayers) {
+  host_impl_->CreatePendingTree();
+  host_impl_->ActivateSyncTree();
+  host_impl_->CreatePendingTree();
+
+  LayerTreeImpl* active_tree = host_impl_->active_tree();
+  LayerTreeImpl* pending_tree = host_impl_->pending_tree();
+  EXPECT_NE(active_tree, pending_tree);
+
+  scoped_ptr<FakePictureLayerImpl> active_layer =
+      FakePictureLayerImpl::Create(active_tree, 10);
+  scoped_ptr<FakePictureLayerImpl> pending_layer =
+      FakePictureLayerImpl::Create(pending_tree, 10);
+
+  std::vector<PairedPictureLayer> paired_layers;
+  host_impl_->GetPairedPictureLayers(&paired_layers);
+
+  EXPECT_EQ(2u, paired_layers.size());
+  if (paired_layers[0].active_layer) {
+    EXPECT_EQ(active_layer.get(), paired_layers[0].active_layer);
+    EXPECT_EQ(NULL, paired_layers[0].pending_layer);
+  } else {
+    EXPECT_EQ(pending_layer.get(), paired_layers[0].pending_layer);
+    EXPECT_EQ(NULL, paired_layers[0].active_layer);
+  }
+
+  if (paired_layers[1].active_layer) {
+    EXPECT_EQ(active_layer.get(), paired_layers[1].active_layer);
+    EXPECT_EQ(NULL, paired_layers[1].pending_layer);
+  } else {
+    EXPECT_EQ(pending_layer.get(), paired_layers[1].pending_layer);
+    EXPECT_EQ(NULL, paired_layers[1].active_layer);
+  }
+
+  active_layer->set_twin_layer(pending_layer.get());
+  pending_layer->set_twin_layer(active_layer.get());
+
+  host_impl_->GetPairedPictureLayers(&paired_layers);
+  EXPECT_EQ(1u, paired_layers.size());
+
+  EXPECT_EQ(active_layer.get(), paired_layers[0].active_layer);
+  EXPECT_EQ(pending_layer.get(), paired_layers[0].pending_layer);
+}
+
 }  // namespace
 }  // namespace cc