// Copyright 2013 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/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"
#include "cc/test/fake_layer_tree_host_impl.h"
#include "cc/test/fake_output_surface.h"
#include "cc/test/fake_output_surface_client.h"
#include "cc/test/fake_picture_layer_impl.h"
#include "cc/test/fake_picture_pile_impl.h"
#include "cc/test/fake_tile_manager.h"
#include "cc/test/impl_side_painting_settings.h"
#include "cc/test/test_shared_bitmap_manager.h"
#include "cc/test/test_tile_priorities.h"
#include "cc/trees/layer_tree_impl.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cc {
namespace {

class LowResTilingsSettings : public ImplSidePaintingSettings {
 public:
  LowResTilingsSettings() { create_low_res_tiling = true; }
};

class TileManagerTilePriorityQueueTest : public testing::Test {
 public:
  TileManagerTilePriorityQueueTest()
      : memory_limit_policy_(ALLOW_ANYTHING),
        max_tiles_(10000),
        ready_to_activate_(false),
        id_(7),
        proxy_(base::MessageLoopProxy::current()),
        host_impl_(LowResTilingsSettings(), &proxy_, &shared_bitmap_manager_) {}

  void SetTreePriority(TreePriority tree_priority) {
    GlobalStateThatImpactsTilePriority state;
    gfx::Size tile_size(256, 256);

    state.soft_memory_limit_in_bytes = 100 * 1000 * 1000;
    state.num_resources_limit = max_tiles_;
    state.hard_memory_limit_in_bytes = state.soft_memory_limit_in_bytes * 2;
    state.memory_limit_policy = memory_limit_policy_;
    state.tree_priority = tree_priority;

    global_state_ = state;
    host_impl_.resource_pool()->SetResourceUsageLimits(
        state.soft_memory_limit_in_bytes,
        state.soft_memory_limit_in_bytes,
        state.num_resources_limit);
    host_impl_.tile_manager()->SetGlobalStateForTesting(state);
  }

  virtual void SetUp() override {
    InitializeRenderer();
    SetTreePriority(SAME_PRIORITY_FOR_BOTH_TREES);
  }

  virtual void InitializeRenderer() {
    host_impl_.InitializeRenderer(FakeOutputSurface::Create3d());
  }

  void SetupDefaultTrees(const gfx::Size& layer_bounds) {
    gfx::Size tile_size(100, 100);

    scoped_refptr<FakePicturePileImpl> pending_pile =
        FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
    scoped_refptr<FakePicturePileImpl> active_pile =
        FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);

    SetupTrees(pending_pile, active_pile);
  }

  void ActivateTree() {
    host_impl_.ActivateSyncTree();
    CHECK(!host_impl_.pending_tree());
    pending_layer_ = NULL;
    active_layer_ = static_cast<FakePictureLayerImpl*>(
        host_impl_.active_tree()->LayerById(id_));
  }

  void SetupDefaultTreesWithFixedTileSize(const gfx::Size& layer_bounds,
                                          const gfx::Size& tile_size) {
    SetupDefaultTrees(layer_bounds);
    pending_layer_->set_fixed_tile_size(tile_size);
    active_layer_->set_fixed_tile_size(tile_size);
  }

  void SetupTrees(scoped_refptr<PicturePileImpl> pending_pile,
                  scoped_refptr<PicturePileImpl> active_pile) {
    SetupPendingTree(active_pile);
    ActivateTree();
    SetupPendingTree(pending_pile);
  }

  void SetupPendingTree(scoped_refptr<PicturePileImpl> pile) {
    host_impl_.CreatePendingTree();
    LayerTreeImpl* pending_tree = host_impl_.pending_tree();
    // Clear recycled tree.
    pending_tree->DetachLayerTree();

    scoped_ptr<FakePictureLayerImpl> pending_layer =
        FakePictureLayerImpl::CreateWithPile(pending_tree, id_, pile);
    pending_layer->SetDrawsContent(true);
    pending_tree->SetRootLayer(pending_layer.Pass());

    pending_layer_ = static_cast<FakePictureLayerImpl*>(
        host_impl_.pending_tree()->LayerById(id_));
    pending_layer_->DoPostCommitInitializationIfNeeded();
  }

  void CreateHighLowResAndSetAllTilesVisible() {
    // Active layer must get updated first so pending layer can share from it.
    active_layer_->CreateDefaultTilingsAndTiles();
    active_layer_->SetAllTilesVisible();
    pending_layer_->CreateDefaultTilingsAndTiles();
    pending_layer_->SetAllTilesVisible();
  }

  TileManager* tile_manager() { return host_impl_.tile_manager(); }

 protected:
  GlobalStateThatImpactsTilePriority global_state_;

  TestSharedBitmapManager shared_bitmap_manager_;
  TileMemoryLimitPolicy memory_limit_policy_;
  int max_tiles_;
  bool ready_to_activate_;
  int id_;
  FakeImplProxy proxy_;
  FakeLayerTreeHostImpl host_impl_;
  FakePictureLayerImpl* pending_layer_;
  FakePictureLayerImpl* active_layer_;
};

TEST_F(TileManagerTilePriorityQueueTest, RasterTilePriorityQueue) {
  SetupDefaultTrees(gfx::Size(1000, 1000));

  active_layer_->CreateDefaultTilingsAndTiles();
  pending_layer_->CreateDefaultTilingsAndTiles();

  RasterTilePriorityQueue queue;
  host_impl_.BuildRasterQueue(&queue, SAME_PRIORITY_FOR_BOTH_TREES);
  EXPECT_FALSE(queue.IsEmpty());

  size_t tile_count = 0;
  std::set<Tile*> all_tiles;
  while (!queue.IsEmpty()) {
    EXPECT_TRUE(queue.Top());
    all_tiles.insert(queue.Top());
    ++tile_count;
    queue.Pop();
  }

  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);

  // Sanity check, all tiles should be visible.
  std::set<Tile*> smoothness_tiles;
  queue.Reset();
  host_impl_.BuildRasterQueue(&queue, SMOOTHNESS_TAKES_PRIORITY);
  bool had_low_res = false;
  while (!queue.IsEmpty()) {
    Tile* tile = queue.Top();
    EXPECT_TRUE(tile);
    EXPECT_EQ(TilePriority::NOW, tile->priority(ACTIVE_TREE).priority_bin);
    EXPECT_EQ(TilePriority::NOW, tile->priority(PENDING_TREE).priority_bin);
    if (tile->priority(ACTIVE_TREE).resolution == LOW_RESOLUTION)
      had_low_res = true;
    else
      smoothness_tiles.insert(tile);
    queue.Pop();
  }
  EXPECT_EQ(all_tiles, smoothness_tiles);
  EXPECT_TRUE(had_low_res);

  Region invalidation(gfx::Rect(0, 0, 500, 500));

  // Invalidate the pending tree.
  pending_layer_->set_invalidation(invalidation);
  pending_layer_->HighResTiling()->UpdateTilesToCurrentPile(
      invalidation, gfx::Size(1000, 1000));
  pending_layer_->LowResTiling()->UpdateTilesToCurrentPile(
      invalidation, gfx::Size(1000, 1000));

  active_layer_->ResetAllTilesPriorities();
  pending_layer_->ResetAllTilesPriorities();

  // Renew all of the tile priorities.
  gfx::Rect viewport(50, 50, 100, 100);
  pending_layer_->HighResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  pending_layer_->LowResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  active_layer_->HighResTiling()->ComputeTilePriorityRects(
      ACTIVE_TREE, viewport, 1.0f, 1.0, Occlusion());
  active_layer_->LowResTiling()->ComputeTilePriorityRects(
      ACTIVE_TREE, viewport, 1.0f, 1.0, Occlusion());

  // Populate all tiles directly from the tilings.
  all_tiles.clear();
  std::set<Tile*> high_res_tiles;
  std::vector<Tile*> pending_high_res_tiles =
      pending_layer_->HighResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < pending_high_res_tiles.size(); ++i) {
    all_tiles.insert(pending_high_res_tiles[i]);
    high_res_tiles.insert(pending_high_res_tiles[i]);
  }

  std::vector<Tile*> pending_low_res_tiles =
      pending_layer_->LowResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < pending_low_res_tiles.size(); ++i)
    all_tiles.insert(pending_low_res_tiles[i]);

  std::vector<Tile*> active_high_res_tiles =
      active_layer_->HighResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < active_high_res_tiles.size(); ++i) {
    all_tiles.insert(active_high_res_tiles[i]);
    high_res_tiles.insert(active_high_res_tiles[i]);
  }

  std::vector<Tile*> active_low_res_tiles =
      active_layer_->LowResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < active_low_res_tiles.size(); ++i)
    all_tiles.insert(active_low_res_tiles[i]);

  Tile* last_tile = NULL;
  smoothness_tiles.clear();
  tile_count = 0;
  size_t correct_order_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();
    EXPECT_TRUE(tile);

    if (!last_tile)
      last_tile = tile;

    EXPECT_LE(last_tile->priority(ACTIVE_TREE).priority_bin,
              tile->priority(ACTIVE_TREE).priority_bin);
    bool skip_updating_last_tile = false;
    if (last_tile->priority(ACTIVE_TREE).priority_bin ==
        tile->priority(ACTIVE_TREE).priority_bin) {
      correct_order_tiles +=
          last_tile->priority(ACTIVE_TREE).distance_to_visible <=
          tile->priority(ACTIVE_TREE).distance_to_visible;
    } else if (tile->priority(ACTIVE_TREE).priority_bin ==
                   TilePriority::EVENTUALLY &&
               tile->priority(PENDING_TREE).priority_bin == TilePriority::NOW) {
      // Since we'd return pending tree now tiles before the eventually tiles on
      // the active tree, update the value.
      ++correct_order_tiles;
      skip_updating_last_tile = true;
    }

    if (tile->priority(ACTIVE_TREE).priority_bin == TilePriority::NOW &&
        last_tile->priority(ACTIVE_TREE).resolution !=
            tile->priority(ACTIVE_TREE).resolution) {
      // Low resolution should come first.
      EXPECT_EQ(LOW_RESOLUTION, last_tile->priority(ACTIVE_TREE).resolution);
    }

    if (!skip_updating_last_tile)
      last_tile = tile;
    ++tile_count;
    smoothness_tiles.insert(tile);
    queue.Pop();
  }

  EXPECT_EQ(tile_count, smoothness_tiles.size());
  EXPECT_EQ(all_tiles, smoothness_tiles);
  // Since we don't guarantee increasing distance due to spiral iterator, we
  // should check that we're _mostly_ right.
  EXPECT_GT(correct_order_tiles, 3 * tile_count / 4);

  std::set<Tile*> new_content_tiles;
  last_tile = NULL;
  size_t increasing_distance_tiles = 0u;
  // Here we expect to get increasing PENDING_TREE priority_bin.
  queue.Reset();
  host_impl_.BuildRasterQueue(&queue, NEW_CONTENT_TAKES_PRIORITY);
  tile_count = 0;
  while (!queue.IsEmpty()) {
    Tile* tile = queue.Top();
    EXPECT_TRUE(tile);

    if (!last_tile)
      last_tile = tile;

    EXPECT_LE(last_tile->priority(PENDING_TREE).priority_bin,
              tile->priority(PENDING_TREE).priority_bin);
    if (last_tile->priority(PENDING_TREE).priority_bin ==
        tile->priority(PENDING_TREE).priority_bin) {
      increasing_distance_tiles +=
          last_tile->priority(PENDING_TREE).distance_to_visible <=
          tile->priority(PENDING_TREE).distance_to_visible;
    }

    if (tile->priority(PENDING_TREE).priority_bin == TilePriority::NOW &&
        last_tile->priority(PENDING_TREE).resolution !=
            tile->priority(PENDING_TREE).resolution) {
      // High resolution should come first.
      EXPECT_EQ(HIGH_RESOLUTION, last_tile->priority(PENDING_TREE).resolution);
    }

    last_tile = tile;
    new_content_tiles.insert(tile);
    ++tile_count;
    queue.Pop();
  }

  EXPECT_EQ(tile_count, new_content_tiles.size());
  EXPECT_EQ(high_res_tiles, new_content_tiles);
  // Since we don't guarantee increasing distance due to spiral iterator, we
  // should check that we're _mostly_ right.
  EXPECT_GE(increasing_distance_tiles, 3 * tile_count / 4);
}

TEST_F(TileManagerTilePriorityQueueTest, EvictionTilePriorityQueue) {
  SetupDefaultTrees(gfx::Size(1000, 1000));

  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::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()) {
    ++tile_count;
    EXPECT_TRUE(raster_queue.Top());
    all_tiles.insert(raster_queue.Top());
    raster_queue.Pop();
  }

  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);

  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());

  // Sanity check, all tiles should be visible.
  std::set<Tile*> smoothness_tiles;
  while (!queue.IsEmpty()) {
    Tile* tile = queue.Top();
    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(
      std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));

  Region invalidation(gfx::Rect(0, 0, 500, 500));

  // Invalidate the pending tree.
  pending_layer_->set_invalidation(invalidation);
  pending_layer_->HighResTiling()->UpdateTilesToCurrentPile(
      invalidation, gfx::Size(1000, 1000));
  pending_layer_->LowResTiling()->UpdateTilesToCurrentPile(
      invalidation, gfx::Size(1000, 1000));

  active_layer_->ResetAllTilesPriorities();
  pending_layer_->ResetAllTilesPriorities();

  // Renew all of the tile priorities.
  gfx::Rect viewport(50, 50, 100, 100);
  pending_layer_->HighResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  pending_layer_->LowResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  active_layer_->HighResTiling()->ComputeTilePriorityRects(
      ACTIVE_TREE, viewport, 1.0f, 1.0, Occlusion());
  active_layer_->LowResTiling()->ComputeTilePriorityRects(
      ACTIVE_TREE, viewport, 1.0f, 1.0, Occlusion());

  // Populate all tiles directly from the tilings.
  all_tiles.clear();
  std::vector<Tile*> pending_high_res_tiles =
      pending_layer_->HighResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < pending_high_res_tiles.size(); ++i)
    all_tiles.insert(pending_high_res_tiles[i]);

  std::vector<Tile*> pending_low_res_tiles =
      pending_layer_->LowResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < pending_low_res_tiles.size(); ++i)
    all_tiles.insert(pending_low_res_tiles[i]);

  std::vector<Tile*> active_high_res_tiles =
      active_layer_->HighResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < active_high_res_tiles.size(); ++i)
    all_tiles.insert(active_high_res_tiles[i]);

  std::vector<Tile*> active_low_res_tiles =
      active_layer_->LowResTiling()->AllTilesForTesting();
  for (size_t i = 0; i < active_low_res_tiles.size(); ++i)
    all_tiles.insert(active_low_res_tiles[i]);

  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();
    EXPECT_TRUE(tile);
    EXPECT_TRUE(tile->HasResources());

    if (!last_tile)
      last_tile = tile;

    EXPECT_GE(last_tile->priority(ACTIVE_TREE).priority_bin,
              tile->priority(ACTIVE_TREE).priority_bin);
    if (last_tile->priority(ACTIVE_TREE).priority_bin ==
        tile->priority(ACTIVE_TREE).priority_bin) {
      EXPECT_LE(last_tile->required_for_activation(),
                tile->required_for_activation());
      if (last_tile->required_for_activation() ==
          tile->required_for_activation()) {
        EXPECT_GE(last_tile->priority(ACTIVE_TREE).distance_to_visible,
                  tile->priority(ACTIVE_TREE).distance_to_visible);
      }
    }

    last_tile = tile;
    ++tile_count;
    smoothness_tiles.insert(tile);
    queue.Pop();
  }

  EXPECT_EQ(tile_count, smoothness_tiles.size());
  EXPECT_EQ(all_tiles, smoothness_tiles);

  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();
    EXPECT_TRUE(tile);

    if (!last_tile)
      last_tile = tile;

    EXPECT_GE(last_tile->priority(PENDING_TREE).priority_bin,
              tile->priority(PENDING_TREE).priority_bin);
    if (last_tile->priority(PENDING_TREE).priority_bin ==
        tile->priority(PENDING_TREE).priority_bin) {
      EXPECT_LE(last_tile->required_for_activation(),
                tile->required_for_activation());
      if (last_tile->required_for_activation() ==
          tile->required_for_activation()) {
        EXPECT_GE(last_tile->priority(PENDING_TREE).distance_to_visible,
                  tile->priority(PENDING_TREE).distance_to_visible);
      }
    }

    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) {
  gfx::Size tile_size(102, 102);
  gfx::Size layer_bounds(1000, 1000);

  scoped_refptr<FakePicturePileImpl> pending_pile =
      FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
  SetupPendingTree(pending_pile);
  pending_layer_->CreateDefaultTilingsAndTiles();

  scoped_ptr<FakePictureLayerImpl> pending_child =
      FakePictureLayerImpl::CreateWithPile(
          host_impl_.pending_tree(), 2, pending_pile);
  pending_layer_->AddChild(pending_child.Pass());

  FakePictureLayerImpl* pending_child_layer =
      static_cast<FakePictureLayerImpl*>(pending_layer_->children()[0]);
  pending_child_layer->SetDrawsContent(true);
  pending_child_layer->DoPostCommitInitializationIfNeeded();
  pending_child_layer->CreateDefaultTilingsAndTiles();

  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()) {
    ++tile_count;
    EXPECT_TRUE(raster_queue.Top());
    all_tiles.insert(raster_queue.Top());
    raster_queue.Pop();
  }
  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(32u, tile_count);

  pending_layer_->ResetAllTilesPriorities();

  // Renew all of the tile priorities.
  gfx::Rect viewport(layer_bounds);
  pending_layer_->HighResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  pending_layer_->LowResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  pending_child_layer->HighResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());
  pending_child_layer->LowResTiling()->ComputeTilePriorityRects(
      PENDING_TREE, viewport, 1.0f, 1.0, Occlusion());

  // Populate all tiles directly from the tilings.
  all_tiles.clear();
  std::vector<Tile*> pending_high_res_tiles =
      pending_layer_->HighResTiling()->AllTilesForTesting();
  all_tiles.insert(pending_high_res_tiles.begin(),
                   pending_high_res_tiles.end());

  std::vector<Tile*> pending_low_res_tiles =
      pending_layer_->LowResTiling()->AllTilesForTesting();
  all_tiles.insert(pending_low_res_tiles.begin(), pending_low_res_tiles.end());

  // Set all tiles on the pending_child_layer as occluded on the pending tree.
  std::vector<Tile*> pending_child_high_res_tiles =
      pending_child_layer->HighResTiling()->AllTilesForTesting();
  pending_child_layer->HighResTiling()->SetAllTilesOccludedForTesting();
  all_tiles.insert(pending_child_high_res_tiles.begin(),
                   pending_child_high_res_tiles.end());

  std::vector<Tile*> pending_child_low_res_tiles =
      pending_child_layer->LowResTiling()->AllTilesForTesting();
  pending_child_layer->LowResTiling()->SetAllTilesOccludedForTesting();
  all_tiles.insert(pending_child_low_res_tiles.begin(),
                   pending_child_low_res_tiles.end());

  tile_manager()->InitializeTilesWithResourcesForTesting(
      std::vector<Tile*>(all_tiles.begin(), all_tiles.end()));

  // Verify occlusion is considered by EvictionTilePriorityQueue.
  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();
    if (!last_tile)
      last_tile = tile;

    bool tile_is_occluded = tile->is_occluded_for_tree_priority(tree_priority);

    // The only way we will encounter an occluded tile after an unoccluded
    // tile is if the priorty bin decreased, the tile is required for
    // activation, or the scale changed.
    if (tile_is_occluded) {
      occluded_count++;

      bool last_tile_is_occluded =
          last_tile->is_occluded_for_tree_priority(tree_priority);
      if (!last_tile_is_occluded) {
        TilePriority::PriorityBin tile_priority_bin =
            tile->priority_for_tree_priority(tree_priority).priority_bin;
        TilePriority::PriorityBin last_tile_priority_bin =
            last_tile->priority_for_tree_priority(tree_priority).priority_bin;

        EXPECT_TRUE((tile_priority_bin < last_tile_priority_bin) ||
                    tile->required_for_activation() ||
                    (tile->contents_scale() != last_tile->contents_scale()));
      }
    }
    last_tile = tile;
    queue.Pop();
  }
  size_t expected_occluded_count =
      pending_child_high_res_tiles.size() + pending_child_low_res_tiles.size();
  EXPECT_EQ(expected_occluded_count, occluded_count);
}

TEST_F(TileManagerTilePriorityQueueTest, RasterTilePriorityQueueEmptyLayers) {
  SetupDefaultTrees(gfx::Size(1000, 1000));

  active_layer_->CreateDefaultTilingsAndTiles();
  pending_layer_->CreateDefaultTilingsAndTiles();

  RasterTilePriorityQueue queue;
  host_impl_.BuildRasterQueue(&queue, SAME_PRIORITY_FOR_BOTH_TREES);
  EXPECT_FALSE(queue.IsEmpty());

  size_t tile_count = 0;
  std::set<Tile*> all_tiles;
  while (!queue.IsEmpty()) {
    EXPECT_TRUE(queue.Top());
    all_tiles.insert(queue.Top());
    ++tile_count;
    queue.Pop();
  }

  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);

  queue.Reset();
  for (int i = 1; i < 10; ++i) {
    scoped_ptr<FakePictureLayerImpl> pending_layer =
        FakePictureLayerImpl::Create(host_impl_.pending_tree(), id_ + i);
    pending_layer->SetDrawsContent(true);
    pending_layer->DoPostCommitInitializationIfNeeded();
    pending_layer->set_has_valid_tile_priorities(true);
    pending_layer_->AddChild(pending_layer.Pass());
  }

  host_impl_.BuildRasterQueue(&queue, SAME_PRIORITY_FOR_BOTH_TREES);
  EXPECT_FALSE(queue.IsEmpty());

  tile_count = 0;
  all_tiles.clear();
  while (!queue.IsEmpty()) {
    EXPECT_TRUE(queue.Top());
    all_tiles.insert(queue.Top());
    ++tile_count;
    queue.Pop();
  }
  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);
}

TEST_F(TileManagerTilePriorityQueueTest, EvictionTilePriorityQueueEmptyLayers) {
  SetupDefaultTrees(gfx::Size(1000, 1000));

  active_layer_->CreateDefaultTilingsAndTiles();
  pending_layer_->CreateDefaultTilingsAndTiles();

  RasterTilePriorityQueue raster_queue;
  host_impl_.BuildRasterQueue(&raster_queue, SAME_PRIORITY_FOR_BOTH_TREES);
  EXPECT_FALSE(raster_queue.IsEmpty());

  size_t tile_count = 0;
  std::set<Tile*> all_tiles;
  while (!raster_queue.IsEmpty()) {
    EXPECT_TRUE(raster_queue.Top());
    all_tiles.insert(raster_queue.Top());
    ++tile_count;
    raster_queue.Pop();
  }
  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);

  std::vector<Tile*> tiles(all_tiles.begin(), all_tiles.end());
  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(tiles);

  EvictionTilePriorityQueue queue;
  for (int i = 1; i < 10; ++i) {
    scoped_ptr<FakePictureLayerImpl> pending_layer =
        FakePictureLayerImpl::Create(host_impl_.pending_tree(), id_ + i);
    pending_layer->SetDrawsContent(true);
    pending_layer->DoPostCommitInitializationIfNeeded();
    pending_layer->set_has_valid_tile_priorities(true);
    pending_layer_->AddChild(pending_layer.Pass());
  }

  host_impl_.BuildEvictionQueue(&queue, SAME_PRIORITY_FOR_BOTH_TREES);
  EXPECT_FALSE(queue.IsEmpty());

  tile_count = 0;
  all_tiles.clear();
  while (!queue.IsEmpty()) {
    EXPECT_TRUE(queue.Top());
    all_tiles.insert(queue.Top());
    ++tile_count;
    queue.Pop();
  }
  EXPECT_EQ(tile_count, all_tiles.size());
  EXPECT_EQ(16u, tile_count);
}

}  // namespace
}  // namespace cc