Revert of cc: Change TileManager iterators to be queues.

cc/resources/tile_manager_unittest.cc

Index: cc/resources/tile_manager_unittest.cc
diff --git a/cc/resources/tile_manager_unittest.cc b/cc/resources/tile_manager_unittest.cc
index a23152b7f546ba69c78a5310f76342e258feaaf7..3dba49b45558c24c372fd64c4f609861f8d9f3cc 100644
--- a/cc/resources/tile_manager_unittest.cc
+++ b/cc/resources/tile_manager_unittest.cc
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "cc/resources/eviction_tile_priority_queue.h"
-#include "cc/resources/raster_tile_priority_queue.h"
 #include "cc/resources/tile.h"
 #include "cc/resources/tile_priority.h"
 #include "cc/test/fake_impl_proxy.h"
@@ -85,16 +83,11 @@
   }
 
   // TileManagerClient implementation.
-  virtual const std::vector<PictureLayerImpl*>& GetPictureLayers()
-      const OVERRIDE {
+  virtual const std::vector<PictureLayerImpl*>& GetPictureLayers() OVERRIDE {
     return picture_layers_;
   }
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
   virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
-  virtual void BuildRasterQueue(RasterTilePriorityQueue* queue,
-                                TreePriority priority) OVERRIDE {}
-  virtual void BuildEvictionQueue(EvictionTilePriorityQueue* queue,
-                                  TreePriority priority) OVERRIDE {}
 
   TileVector CreateTilesWithSize(int count,
                                  TilePriority active_priority,
@@ -431,9 +424,9 @@
                         TileManagerTest,
                         ::testing::Values(true, false));
 
-class TileManagerTilePriorityQueueTest : public testing::Test {
+class TileManagerTileIteratorTest : public testing::Test {
  public:
-  TileManagerTilePriorityQueueTest()
+  TileManagerTileIteratorTest()
       : memory_limit_policy_(ALLOW_ANYTHING),
         max_tiles_(10000),
         ready_to_activate_(false),
@@ -544,23 +537,75 @@
   FakePictureLayerImpl* active_layer_;
 };
 
-TEST_F(TileManagerTilePriorityQueueTest, RasterTilePriorityQueue) {
+TEST_F(TileManagerTileIteratorTest, 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);
+
+  TileManager* tile_manager = TileManagerTileIteratorTest::tile_manager();
+  EXPECT_TRUE(tile_manager);
+
+  std::vector<TileManager::PairedPictureLayer> paired_layers;
+  tile_manager->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());
+
+  tile_manager->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);
+}
+
+TEST_F(TileManagerTileIteratorTest, RasterTileIterator) {
   SetupDefaultTrees(gfx::Size(1000, 1000));
+  TileManager* tile_manager = TileManagerTileIteratorTest::tile_manager();
+  EXPECT_TRUE(tile_manager);
 
   active_layer_->CreateDefaultTilingsAndTiles();
   pending_layer_->CreateDefaultTilingsAndTiles();
 
-  RasterTilePriorityQueue queue;
-  host_impl_.BuildRasterQueue(&queue, SAME_PRIORITY_FOR_BOTH_TREES);
-  EXPECT_FALSE(queue.IsEmpty());
+  std::vector<TileManager::PairedPictureLayer> paired_layers;
+  tile_manager->GetPairedPictureLayers(&paired_layers);
+  EXPECT_EQ(1u, paired_layers.size());
+
+  TileManager::RasterTileIterator it(tile_manager,
+                                     SAME_PRIORITY_FOR_BOTH_TREES);
+  EXPECT_TRUE(it);
 
   size_t tile_count = 0;
   std::set<Tile*> all_tiles;
-  while (!queue.IsEmpty()) {
-    EXPECT_TRUE(queue.Top());
-    all_tiles.insert(queue.Top());
+  for (; it; ++it) {
+    EXPECT_TRUE(*it);
+    all_tiles.insert(*it);
     ++tile_count;
-    queue.Pop();
   }
 
   EXPECT_EQ(tile_count, all_tiles.size());
@@ -568,15 +613,15 @@
 
   // Sanity check, all tiles should be visible.
   std::set<Tile*> smoothness_tiles;
-  queue.Reset();
-  host_impl_.BuildRasterQueue(&queue, SMOOTHNESS_TAKES_PRIORITY);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::RasterTileIterator it(tile_manager,
+                                          SMOOTHNESS_TAKES_PRIORITY);
+       it;
+       ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
     EXPECT_EQ(TilePriority::NOW, tile->priority(ACTIVE_TREE).priority_bin);
     EXPECT_EQ(TilePriority::NOW, tile->priority(PENDING_TREE).priority_bin);
     smoothness_tiles.insert(tile);
-    queue.Pop();
   }
   EXPECT_EQ(all_tiles, smoothness_tiles);
 
@@ -654,10 +699,11 @@
   tile_count = 0;
   size_t increasing_distance_tiles = 0u;
   // Here we expect to get increasing ACTIVE_TREE priority_bin.
-  queue.Reset();
-  host_impl_.BuildRasterQueue(&queue, SMOOTHNESS_TAKES_PRIORITY);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::RasterTileIterator it(tile_manager,
+                                          SMOOTHNESS_TAKES_PRIORITY);
+       it;
+       ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
 
     if (!last_tile)
@@ -682,7 +728,6 @@
     last_tile = tile;
     ++tile_count;
     smoothness_tiles.insert(tile);
-    queue.Pop();
   }
 
   EXPECT_EQ(tile_count, smoothness_tiles.size());
@@ -695,10 +740,11 @@
   last_tile = NULL;
   increasing_distance_tiles = 0u;
   // Here we expect to get increasing PENDING_TREE priority_bin.
-  queue.Reset();
-  host_impl_.BuildRasterQueue(&queue, NEW_CONTENT_TAKES_PRIORITY);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::RasterTileIterator it(tile_manager,
+                                          NEW_CONTENT_TAKES_PRIORITY);
+       it;
+       ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
 
     if (!last_tile)
@@ -722,7 +768,6 @@
 
     last_tile = tile;
     new_content_tiles.insert(tile);
-    queue.Pop();
   }
 
   EXPECT_EQ(tile_count, new_content_tiles.size());
@@ -732,51 +777,55 @@
   EXPECT_GT(increasing_distance_tiles, 3 * tile_count / 4);
 }
 
-TEST_F(TileManagerTilePriorityQueueTest, EvictionTilePriorityQueue) {
+TEST_F(TileManagerTileIteratorTest, EvictionTileIterator) {
   SetupDefaultTrees(gfx::Size(1000, 1000));
+  TileManager* tile_manager = TileManagerTileIteratorTest::tile_manager();
+  EXPECT_TRUE(tile_manager);
 
   active_layer_->CreateDefaultTilingsAndTiles();
   pending_layer_->CreateDefaultTilingsAndTiles();
 
-  EvictionTilePriorityQueue empty_queue;
-  host_impl_.BuildEvictionQueue(&empty_queue, SAME_PRIORITY_FOR_BOTH_TREES);
-  EXPECT_TRUE(empty_queue.IsEmpty());
+  std::vector<TileManager::PairedPictureLayer> paired_layers;
+  tile_manager->GetPairedPictureLayers(&paired_layers);
+  EXPECT_EQ(1u, paired_layers.size());
+
+  TileManager::EvictionTileIterator empty_it(tile_manager,
+                                             SAME_PRIORITY_FOR_BOTH_TREES);
+  EXPECT_FALSE(empty_it);
   std::set<Tile*> all_tiles;
   size_t tile_count = 0;
 
-  RasterTilePriorityQueue raster_queue;
-  host_impl_.BuildRasterQueue(&raster_queue, SAME_PRIORITY_FOR_BOTH_TREES);
-  while (!raster_queue.IsEmpty()) {
+  for (TileManager::RasterTileIterator raster_it(tile_manager,
+                                                 SAME_PRIORITY_FOR_BOTH_TREES);
+       raster_it;
+       ++raster_it) {
     ++tile_count;
-    EXPECT_TRUE(raster_queue.Top());
-    all_tiles.insert(raster_queue.Top());
-    raster_queue.Pop();
+    EXPECT_TRUE(*raster_it);
+    all_tiles.insert(*raster_it);
   }
 
   EXPECT_EQ(tile_count, all_tiles.size());
   EXPECT_EQ(17u, tile_count);
 
-  tile_manager()->InitializeTilesWithResourcesForTesting(
+  tile_manager->InitializeTilesWithResourcesForTesting(
       std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));
 
-  EvictionTilePriorityQueue queue;
-  host_impl_.BuildEvictionQueue(&queue, SMOOTHNESS_TAKES_PRIORITY);
-  EXPECT_FALSE(queue.IsEmpty());
+  TileManager::EvictionTileIterator it(tile_manager, SMOOTHNESS_TAKES_PRIORITY);
+  EXPECT_TRUE(it);
 
   // Sanity check, all tiles should be visible.
   std::set<Tile*> smoothness_tiles;
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (; it; ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
     EXPECT_EQ(TilePriority::NOW, tile->priority(ACTIVE_TREE).priority_bin);
     EXPECT_EQ(TilePriority::NOW, tile->priority(PENDING_TREE).priority_bin);
     EXPECT_TRUE(tile->HasResources());
     smoothness_tiles.insert(tile);
-    queue.Pop();
   }
   EXPECT_EQ(all_tiles, smoothness_tiles);
 
-  tile_manager()->ReleaseTileResourcesForTesting(
+  tile_manager->ReleaseTileResourcesForTesting(
       std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));
 
   Region invalidation(gfx::Rect(0, 0, 500, 500));
@@ -848,17 +897,18 @@
   for (size_t i = 0; i < active_low_res_tiles.size(); ++i)
     all_tiles.insert(active_low_res_tiles[i]);
 
-  tile_manager()->InitializeTilesWithResourcesForTesting(
+  tile_manager->InitializeTilesWithResourcesForTesting(
       std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));
 
   Tile* last_tile = NULL;
   smoothness_tiles.clear();
   tile_count = 0;
   // Here we expect to get increasing ACTIVE_TREE priority_bin.
-  queue.Reset();
-  host_impl_.BuildEvictionQueue(&queue, SMOOTHNESS_TAKES_PRIORITY);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::EvictionTileIterator it(tile_manager,
+                                            SMOOTHNESS_TAKES_PRIORITY);
+       it;
+       ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
     EXPECT_TRUE(tile->HasResources());
 
@@ -876,7 +926,6 @@
     last_tile = tile;
     ++tile_count;
     smoothness_tiles.insert(tile);
-    queue.Pop();
   }
 
   EXPECT_EQ(tile_count, smoothness_tiles.size());
@@ -885,10 +934,11 @@
   std::set<Tile*> new_content_tiles;
   last_tile = NULL;
   // Here we expect to get increasing PENDING_TREE priority_bin.
-  queue.Reset();
-  host_impl_.BuildEvictionQueue(&queue, NEW_CONTENT_TAKES_PRIORITY);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::EvictionTileIterator it(tile_manager,
+                                            NEW_CONTENT_TAKES_PRIORITY);
+       it;
+       ++it) {
+    Tile* tile = *it;
     EXPECT_TRUE(tile);
 
     if (!last_tile)
@@ -904,15 +954,13 @@
 
     last_tile = tile;
     new_content_tiles.insert(tile);
-    queue.Pop();
   }
 
   EXPECT_EQ(tile_count, new_content_tiles.size());
   EXPECT_EQ(all_tiles, new_content_tiles);
 }
 
-TEST_F(TileManagerTilePriorityQueueTest,
-       EvictionTilePriorityQueueWithOcclusion) {
+TEST_F(TileManagerTileIteratorTest, EvictionTileIteratorWithOcclusion) {
   gfx::Size tile_size(102, 102);
   gfx::Size layer_bounds(1000, 1000);
 
@@ -932,15 +980,22 @@
   pending_child_layer->DoPostCommitInitializationIfNeeded();
   pending_child_layer->CreateDefaultTilingsAndTiles();
 
+  TileManager* tile_manager = TileManagerTileIteratorTest::tile_manager();
+  EXPECT_TRUE(tile_manager);
+
+  std::vector<TileManager::PairedPictureLayer> paired_layers;
+  tile_manager->GetPairedPictureLayers(&paired_layers);
+  EXPECT_EQ(2u, paired_layers.size());
+
   std::set<Tile*> all_tiles;
   size_t tile_count = 0;
-  RasterTilePriorityQueue raster_queue;
-  host_impl_.BuildRasterQueue(&raster_queue, SAME_PRIORITY_FOR_BOTH_TREES);
-  while (!raster_queue.IsEmpty()) {
+  for (TileManager::RasterTileIterator raster_it(tile_manager,
+                                                 NEW_CONTENT_TAKES_PRIORITY);
+       raster_it;
+       ++raster_it) {
     ++tile_count;
-    EXPECT_TRUE(raster_queue.Top());
-    all_tiles.insert(raster_queue.Top());
-    raster_queue.Pop();
+    EXPECT_TRUE(*raster_it);
+    all_tiles.insert(*raster_it);
   }
   EXPECT_EQ(tile_count, all_tiles.size());
   EXPECT_EQ(34u, tile_count);
@@ -1009,17 +1064,16 @@
     all_tiles.insert(pending_child_low_res_tiles[i]);
   }
 
-  tile_manager()->InitializeTilesWithResourcesForTesting(
+  tile_manager->InitializeTilesWithResourcesForTesting(
       std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));
 
-  // Verify occlusion is considered by EvictionTilePriorityQueue.
+  // Verify occlusion is considered by EvictionTileIterator.
   TreePriority tree_priority = NEW_CONTENT_TAKES_PRIORITY;
   size_t occluded_count = 0u;
   Tile* last_tile = NULL;
-  EvictionTilePriorityQueue queue;
-  host_impl_.BuildEvictionQueue(&queue, tree_priority);
-  while (!queue.IsEmpty()) {
-    Tile* tile = queue.Top();
+  for (TileManager::EvictionTileIterator it(tile_manager, tree_priority); it;
+       ++it) {
+    Tile* tile = *it;
     if (!last_tile)
       last_tile = tile;
 
@@ -1045,7 +1099,6 @@
       }
     }
     last_tile = tile;
-    queue.Pop();
   }
   size_t expected_occluded_count =
       pending_child_high_res_tiles.size() + pending_child_low_res_tiles.size();