Reland of: cc: Add occlusion checker as a fixed view of occlusion tracker.

cc/resources/picture_layer_tiling_unittest.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.h"
 
 #include <limits>
 #include <set>
 
 #include "cc/base/math_util.h"
@@ skipping 26 matching lines @@
 static void UpdateAllTilePriorities(PictureLayerTilingSet* set,
                                     WhichTree tree,
                                     const gfx::Rect& visible_layer_rect,
                                     float layer_contents_scale,
                                     double current_frame_time_in_seconds) {
   for (size_t i = 0; i < set->num_tilings(); ++i) {
     set->tiling_at(i)->UpdateTilePriorities(tree,
                                             visible_layer_rect,
                                             layer_contents_scale,
                                             current_frame_time_in_seconds,
-                                            NULL,
-                                            NULL,
-                                            gfx::Transform());
+                                            OcclusionChecker<LayerImpl>());
   }
 }
 
 class TestablePictureLayerTiling : public PictureLayerTiling {
  public:
   using PictureLayerTiling::SetLiveTilesRect;
   using PictureLayerTiling::TileAt;
 
   static scoped_ptr<TestablePictureLayerTiling> Create(
       float contents_scale,
@@ skipping 474 matching lines @@
   client.set_tree(ACTIVE_TREE);
   scoped_ptr<TestablePictureLayerTiling> tiling;
 
   gfx::Rect viewport(0, 0, 100, 100);
   gfx::Size layer_bounds(200, 200);
 
   client.SetTileSize(gfx::Size(100, 100));
   tiling = TestablePictureLayerTiling::Create(1.0f, layer_bounds, &client);
 
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.f, 1.0, OcclusionChecker<LayerImpl>());
 
   // Move viewport down 50 pixels in 0.5 seconds.
   gfx::Rect down_skewport =
       tiling->ComputeSkewport(1.5, gfx::Rect(0, 50, 100, 100));
 
   EXPECT_EQ(0, down_skewport.x());
   EXPECT_EQ(50, down_skewport.y());
   EXPECT_EQ(100, down_skewport.width());
   EXPECT_EQ(175, down_skewport.height());
   EXPECT_TRUE(down_skewport.Contains(gfx::Rect(0, 50, 100, 100)));
@@ skipping 46 matching lines @@
   scoped_ptr<TestablePictureLayerTiling> tiling;
 
   gfx::Rect viewport(0, 0, 100, 100);
   gfx::Size layer_bounds(200, 200);
 
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f, layer_bounds, &client);
 
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.f, 1.0, OcclusionChecker<LayerImpl>());
 
   // Move viewport down 50 pixels in 0.5 seconds.
   gfx::Rect down_skewport =
       tiling->ComputeSkewport(1.5, gfx::Rect(0, 50, 100, 100));
 
   EXPECT_EQ(0, down_skewport.x());
   EXPECT_EQ(50, down_skewport.y());
   EXPECT_EQ(100, down_skewport.width());
   EXPECT_EQ(200, down_skewport.height());
 
@@ skipping 47 matching lines @@
   // Tiling at 0.25 scale: this should create 47x47 tiles of size 10x10.
   // The reason is that each tile has a one pixel border, so tile at (1, 2)
   // for instance begins at (8, 16) pixels. So tile at (46, 46) will begin at
   // (368, 368) and extend to the end of 1500 * 0.25 = 375 edge of the
   // tiling.
   tiling = TestablePictureLayerTiling::Create(0.25f, layer_bounds, &client);
   gfx::Rect viewport_in_content_space =
       gfx::ToEnclosedRect(gfx::ScaleRect(viewport, 0.25f));
 
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.f, 1.0, OcclusionChecker<LayerImpl>());
 
   gfx::Rect soon_rect = viewport;
   soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
   gfx::Rect soon_rect_in_content_space =
       gfx::ToEnclosedRect(gfx::ScaleRect(soon_rect, 0.25f));
 
   // Sanity checks.
   for (int i = 0; i < 47; ++i) {
     for (int j = 0; j < 47; ++j) {
       EXPECT_TRUE(tiling->TileAt(i, j)) << "i: " << i << " j: " << j;
@@ skipping 64 matching lines @@
   soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
   soon_rect_in_content_space =
       gfx::ToEnclosedRect(gfx::ScaleRect(soon_rect, 0.25f));
 
   EXPECT_EQ(0, skewport.x());
   EXPECT_EQ(10, skewport.y());
   EXPECT_EQ(25, skewport.width());
   EXPECT_EQ(35, skewport.height());
 
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.f, 2.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.f, 2.0, OcclusionChecker<LayerImpl>());
 
   have_now = false;
   have_eventually = false;
   have_soon = false;
 
   // Viewport moved, so we expect to find some NOW tiles, some SOON tiles and
   // some EVENTUALLY tiles.
   for (int i = 0; i < 47; ++i) {
     for (int j = 0; j < 47; ++j) {
       Tile* tile = tiling->TileAt(i, j);
@@ skipping 31 matching lines @@
   EXPECT_FLOAT_EQ(68.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(2, 5)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(28.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(3, 4)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(4.f, priority.distance_to_visible);
 
   // Change the underlying layer scale.
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 2.0f, 3.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 2.0f, 3.0, OcclusionChecker<LayerImpl>());
 
   priority = tiling->TileAt(5, 1)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(136.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(2, 5)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(56.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(3, 4)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(8.f, priority.distance_to_visible);
 
   // Test additional scales.
   tiling = TestablePictureLayerTiling::Create(0.2f, layer_bounds, &client);
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.0f, 4.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.0f, 4.0, OcclusionChecker<LayerImpl>());
 
   priority = tiling->TileAt(5, 1)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(110.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(2, 5)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(70.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(3, 4)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(60.f, priority.distance_to_visible);
 
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 0.5f, 5.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 0.5f, 5.0, OcclusionChecker<LayerImpl>());
 
   priority = tiling->TileAt(5, 1)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(55.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(2, 5)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(35.f, priority.distance_to_visible);
 
   priority = tiling->TileAt(3, 4)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(30.f, priority.distance_to_visible);
 }
@@ skipping 224 matching lines @@
   gfx::Size layer_bounds(800, 800);
 
   gfx::Rect soon_rect = viewport;
   soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
 
   client.SetTileSize(gfx::Size(30, 30));
   client.set_tree(ACTIVE_TREE);
 
   tiling = TestablePictureLayerTiling::Create(1.0f, layer_bounds, &client);
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.0f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.0f, 1.0, OcclusionChecker<LayerImpl>());
 
   PictureLayerTiling::TilingRasterTileIterator empty_iterator;
   EXPECT_FALSE(empty_iterator);
 
   std::vector<Tile*> all_tiles = tiling->AllTilesForTesting();
 
   // Sanity check.
   EXPECT_EQ(841u, all_tiles.size());
 
   // The explanation of each iteration is as follows:
@@ skipping 88 matching lines @@
 
   gfx::Rect viewport(50, 0, 100, 100);
   gfx::Rect moved_viewport(50, 0, 100, 500);
   gfx::Size layer_bounds(1000, 1000);
 
   client.SetTileSize(gfx::Size(30, 30));
   client.set_tree(ACTIVE_TREE);
 
   tiling = TestablePictureLayerTiling::Create(1.f, layer_bounds, &client);
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.0f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.0f, 1.0, OcclusionChecker<LayerImpl>());
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, moved_viewport, 1.0f, 2.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, moved_viewport, 1.0f, 2.0, OcclusionChecker<LayerImpl>());
 
   gfx::Rect soon_rect = moved_viewport;
   soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
 
   // There are 3 bins in TilePriority.
   bool have_tiles[3] = {};
   Tile* last_tile = NULL;
   int eventually_bin_order_correct_count = 0;
   int eventually_bin_order_incorrect_count = 0;
   for (PictureLayerTiling::TilingRasterTileIterator it(tiling.get(),
@@ skipping 53 matching lines @@
   scoped_ptr<TestablePictureLayerTiling> tiling;
 
   gfx::Rect viewport(50, 50, 100, 100);
   gfx::Size layer_bounds(2000, 2000);
 
   client.SetTileSize(gfx::Size(30, 30));
   client.set_tree(ACTIVE_TREE);
 
   tiling = TestablePictureLayerTiling::Create(1.0f, layer_bounds, &client);
   tiling->UpdateTilePriorities(
-      ACTIVE_TREE, viewport, 1.0f, 1.0, NULL, NULL, gfx::Transform());
+      ACTIVE_TREE, viewport, 1.0f, 1.0, OcclusionChecker<LayerImpl>());
 
   PictureLayerTiling::TilingRasterTileIterator empty_iterator;
   EXPECT_FALSE(empty_iterator);
 
   std::vector<Tile*> all_tiles = tiling->AllTilesForTesting();
 
   PictureLayerTiling::TilingEvictionTileIterator it(
       tiling.get(), SMOOTHNESS_TAKES_PRIORITY, PictureLayerTiling::NOW);
 
   // Tiles don't have resources to evict.
@@ skipping 57 matching lines @@
   Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
   VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 
   client_.set_tree(ACTIVE_TREE);
   tiling_->UpdateTilePriorities(
       ACTIVE_TREE,
       gfx::Rect(layer_bounds),  // visible content rect
       1.f,                      // current contents scale
       1.0,                      // current frame time
-      NULL,                     // occlusion tracker
-      NULL,                     // render target
-      gfx::Transform());        // draw transform
+      OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
 
   // Make the viewport rect empty. All tiles are killed and become zombies.
   tiling_->UpdateTilePriorities(ACTIVE_TREE,
-                                gfx::Rect(),        // visible content rect
-                                1.f,                // current contents scale
-                                2.0,                // current frame time
-                                NULL,               // occlusion tracker
-                                NULL,               // render target
-                                gfx::Transform());  // draw transform
+                                gfx::Rect(),  // visible content rect
+                                1.f,          // current contents scale
+                                2.0,          // current frame time
+                                OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 }
 
 TEST_F(PictureLayerTilingIteratorTest, TilesExistGiantViewport) {
   gfx::Size layer_bounds(1099, 801);
   Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
   VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 
   gfx::Rect giant_rect(-10000000, -10000000, 1000000000, 1000000000);
 
   client_.set_tree(ACTIVE_TREE);
   tiling_->UpdateTilePriorities(
       ACTIVE_TREE,
       gfx::Rect(layer_bounds),  // visible content rect
       1.f,                      // current contents scale
       1.0,                      // current frame time
-      NULL,                     // occlusion tracker
-      NULL,                     // render target
-      gfx::Transform());        // draw transform
+      OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
 
   // If the visible content rect is empty, it should still have live tiles.
   tiling_->UpdateTilePriorities(ACTIVE_TREE,
-                                giant_rect,         // visible content rect
-                                1.f,                // current contents scale
-                                2.0,                // current frame time
-                                NULL,               // occlusion tracker
-                                NULL,               // render target
-                                gfx::Transform());  // draw transform
+                                giant_rect,  // visible content rect
+                                1.f,         // current contents scale
+                                2.0,         // current frame time
+                                OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
 }
 
 TEST_F(PictureLayerTilingIteratorTest, TilesExistOutsideViewport) {
   gfx::Size layer_bounds(1099, 801);
   Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
   VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 
   // This rect does not intersect with the layer, as the layer is outside the
   // viewport.
   gfx::Rect viewport_rect(1100, 0, 1000, 1000);
   EXPECT_FALSE(viewport_rect.Intersects(gfx::Rect(layer_bounds)));
 
   client_.set_tree(ACTIVE_TREE);
   tiling_->UpdateTilePriorities(ACTIVE_TREE,
-                                viewport_rect,      // visible content rect
-                                1.f,                // current contents scale
-                                1.0,                // current frame time
-                                NULL,               // occlusion tracker
-                                NULL,               // render target
-                                gfx::Transform());  // draw transform
+                                viewport_rect,  // visible content rect
+                                1.f,            // current contents scale
+                                1.0,            // current frame time
+                                OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, true));
 }
 
 static void TilesIntersectingRectExist(const gfx::Rect& rect,
                                        bool intersect_exists,
                                        Tile* tile,
                                        const gfx::Rect& geometry_rect) {
   bool intersects = rect.Intersects(geometry_rect);
   bool expected_exists = intersect_exists ? intersects : !intersects;
   EXPECT_EQ(expected_exists, tile != NULL)
       << "Rects intersecting " << rect.ToString() << " should exist. "
       << "Current tile rect is " << geometry_rect.ToString();
 }
 
 TEST_F(PictureLayerTilingIteratorTest,
        TilesExistLargeViewportAndLayerWithSmallVisibleArea) {
   gfx::Size layer_bounds(10000, 10000);
   Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
   VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 
   gfx::Rect visible_rect(8000, 8000, 50, 50);
 
   client_.set_tree(ACTIVE_TREE);
   set_max_tiles_for_interest_area(1);
   tiling_->UpdateTilePriorities(ACTIVE_TREE,
-                                visible_rect,       // visible content rect
-                                1.f,                // current contents scale
-                                1.0,                // current frame time
-                                NULL,               // occlusion tracker
-                                NULL,               // render target
-                                gfx::Transform());  // draw transform
+                                visible_rect,  // visible content rect
+                                1.f,           // current contents scale
+                                1.0,           // current frame time
+                                OcclusionChecker<LayerImpl>());
   VerifyTiles(1.f,
               gfx::Rect(layer_bounds),
               base::Bind(&TilesIntersectingRectExist, visible_rect, true));
 }
 
 static void CountExistingTiles(int *count,
                                Tile* tile,
                                const gfx::Rect& geometry_rect) {
   if (tile != NULL)
     ++(*count);
 }
 
 TEST_F(PictureLayerTilingIteratorTest,
        TilesExistLargeViewportAndLayerWithLargeVisibleArea) {
   gfx::Size layer_bounds(10000, 10000);
   Initialize(gfx::Size(100, 100), 1.f, layer_bounds);
   VerifyTilesExactlyCoverRect(1.f, gfx::Rect(layer_bounds));
   VerifyTiles(1.f, gfx::Rect(layer_bounds), base::Bind(&TileExists, false));
 
   client_.set_tree(ACTIVE_TREE);
   set_max_tiles_for_interest_area(1);
   tiling_->UpdateTilePriorities(
       ACTIVE_TREE,
       gfx::Rect(layer_bounds),  // visible content rect
       1.f,                      // current contents scale
       1.0,                      // current frame time
-      NULL,                     // occlusion tracker
-      NULL,                     // render target
-      gfx::Transform());        // draw transform
+      OcclusionChecker<LayerImpl>());
 
   int num_tiles = 0;
   VerifyTiles(1.f,
               gfx::Rect(layer_bounds),
               base::Bind(&CountExistingTiles, &num_tiles));
   // If we're making a rect the size of one tile, it can only overlap up to 4
   // tiles depending on its position.
   EXPECT_LE(num_tiles, 4);
   VerifyTiles(1.f, gfx::Rect(), base::Bind(&TileExists, false));
 }
@@ skipping 71 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 34 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_GT(priority.distance_to_visible, 0.f);
   EXPECT_NE(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 44 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_FLOAT_EQ(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 38 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_EQ(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 62 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   // All tiles will have a positive distance_to_visible
   // and an infinite time_to_visible.
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(priority.distance_to_visible, 0.f);
@@ skipping 72 matching lines @@
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   // Left-side tiles will be clipped by the transform, so we have to assume
   // they are visible just in case.
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
@@ skipping 43 matching lines @@
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   // previous ("last") frame
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                last_layer_contents_scale,
                                last_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   // current frame
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_GT(priority.distance_to_visible, 0.f);
   EXPECT_NE(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 50 matching lines @@
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               current_layer_bounds,
                                               &client);
 
   // previous ("last") frame
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                last_layer_contents_scale,
                                last_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   // current frame
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                viewport_in_layer_space,
                                current_layer_contents_scale,
                                current_frame_time_in_seconds,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   ASSERT_TRUE(tiling->TileAt(0, 0));
   ASSERT_TRUE(tiling->TileAt(0, 1));
   ASSERT_TRUE(tiling->TileAt(1, 0));
   ASSERT_TRUE(tiling->TileAt(1, 1));
 
   TilePriority priority = tiling->TileAt(0, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_EQ(TilePriority::NOW, priority.priority_bin);
 
@@ skipping 12 matching lines @@
 
   client.SetTileSize(gfx::Size(100, 100));
   client.set_tree(ACTIVE_TREE);
   tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                               gfx::Size(100, 100),
                                               &client);
   tiling->UpdateTilePriorities(ACTIVE_TREE,
                                gfx::Rect(0, 0, 100, 100),
                                1.0f,
                                1.0f,
-                               NULL,               // occlusion tracker
-                               NULL,               // render target
-                               gfx::Transform());  // draw transform
+                               OcclusionChecker<LayerImpl>());
 
   std::vector<scoped_refptr<Tile> > tiles = tiling->AllRefTilesForTesting();
   ASSERT_GT(tiles.size(), 0u);
   for (std::vector<scoped_refptr<Tile> >::const_iterator it = tiles.begin();
        it != tiles.end();
        ++it) {
     EXPECT_NE(TilePriority(), (*it)->priority(ACTIVE_TREE));
   }
 
   tiling->Reset();
@@ skipping 23 matching lines @@
   active_client.set_tree(ACTIVE_TREE);
   active_client.set_max_tiles_for_interest_area(10);
   active_tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                                      gfx::Size(10000, 10000),
                                                      &active_client);
   // Create all tiles on this tiling.
   active_tiling->UpdateTilePriorities(ACTIVE_TREE,
                                       gfx::Rect(0, 0, 100, 100),
                                       1.0f,
                                       1.0f,
-                                      NULL,               // occlusion tracker
-                                      NULL,               // render target
-                                      gfx::Transform());  // draw transform
+                                      OcclusionChecker<LayerImpl>());
 
   FakePictureLayerTilingClient recycle_client;
   recycle_client.SetTileSize(gfx::Size(100, 100));
   recycle_client.set_tree(PENDING_TREE);
   recycle_client.set_twin_tiling(active_tiling.get());
   recycle_client.set_max_tiles_for_interest_area(10);
 
   scoped_ptr<TestablePictureLayerTiling> recycle_tiling;
   recycle_tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                                       gfx::Size(10000, 10000),
                                                       &recycle_client);
 
   // Create all tiles on the second tiling. All tiles should be shared.
   recycle_tiling->UpdateTilePriorities(PENDING_TREE,
                                        gfx::Rect(0, 0, 100, 100),
                                        1.0f,
                                        1.0f,
-                                       NULL,               // occlusion tracker
-                                       NULL,               // render target
-                                       gfx::Transform());  // draw transform
+                                       OcclusionChecker<LayerImpl>());
 
   // Set the second tiling as recycled.
   active_client.set_twin_tiling(NULL);
   active_client.set_recycled_twin_tiling(recycle_tiling.get());
   recycle_client.set_twin_tiling(NULL);
 
   // Verify that tiles exist and are shared.
   EXPECT_TRUE(active_tiling->TileAt(0, 0));
   EXPECT_TRUE(recycle_tiling->TileAt(0, 0));
   EXPECT_EQ(active_tiling->TileAt(0, 0), recycle_tiling->TileAt(0, 0));
 
   // Move the viewport far away from the (0, 0) tile.
   active_tiling->UpdateTilePriorities(ACTIVE_TREE,
                                       gfx::Rect(9000, 9000, 100, 100),
                                       1.0f,
                                       2.0,
-                                      NULL,               // occlusion tracker
-                                      NULL,               // render target
-                                      gfx::Transform());  // draw transform
+                                      OcclusionChecker<LayerImpl>());
   // Ensure the tile was deleted on both tilings.
   EXPECT_FALSE(active_tiling->TileAt(0, 0));
   EXPECT_FALSE(recycle_tiling->TileAt(0, 0));
 
   // Move the viewport back to (0, 0) tile.
   active_tiling->UpdateTilePriorities(ACTIVE_TREE,
                                       gfx::Rect(0, 0, 100, 100),
                                       1.0f,
                                       3.0,
-                                      NULL,               // occlusion tracker
-                                      NULL,               // render target
-                                      gfx::Transform());  // draw transform
+                                      OcclusionChecker<LayerImpl>());
 
   // Ensure that we now have a tile here, but the recycle tiling does not.
   EXPECT_TRUE(active_tiling->TileAt(0, 0));
   EXPECT_FALSE(recycle_tiling->TileAt(0, 0));
 }
 
 TEST(PictureLayerTilingTest, RecycledTilesClearedOnReset) {
   FakePictureLayerTilingClient active_client;
   scoped_ptr<TestablePictureLayerTiling> active_tiling;
 
   active_client.SetTileSize(gfx::Size(100, 100));
   active_client.set_tree(ACTIVE_TREE);
   active_tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                                      gfx::Size(100, 100),
                                                      &active_client);
   // Create all tiles on this tiling.
   active_tiling->UpdateTilePriorities(ACTIVE_TREE,
                                       gfx::Rect(0, 0, 100, 100),
                                       1.0f,
                                       1.0f,
-                                      NULL,               // occlusion tracker
-                                      NULL,               // render target
-                                      gfx::Transform());  // draw transform
+                                      OcclusionChecker<LayerImpl>());
 
   FakePictureLayerTilingClient recycle_client;
   recycle_client.SetTileSize(gfx::Size(100, 100));
   recycle_client.set_tree(PENDING_TREE);
   recycle_client.set_twin_tiling(active_tiling.get());
   recycle_client.set_max_tiles_for_interest_area(10);
 
   scoped_ptr<TestablePictureLayerTiling> recycle_tiling;
   recycle_tiling = TestablePictureLayerTiling::Create(1.0f,  // contents_scale
                                                       gfx::Size(100, 100),
                                                       &recycle_client);
 
   // Create all tiles on the recycle tiling. All tiles should be shared.
   recycle_tiling->UpdateTilePriorities(PENDING_TREE,
                                        gfx::Rect(0, 0, 100, 100),
                                        1.0f,
                                        1.0f,
-                                       NULL,               // occlusion tracker
-                                       NULL,               // render target
-                                       gfx::Transform());  // draw transform
+                                       OcclusionChecker<LayerImpl>());
 
   // Set the second tiling as recycled.
   active_client.set_twin_tiling(NULL);
   active_client.set_recycled_twin_tiling(recycle_tiling.get());
   recycle_client.set_twin_tiling(NULL);
 
   // Verify that tiles exist and are shared.
   EXPECT_TRUE(active_tiling->TileAt(0, 0));
   EXPECT_TRUE(recycle_tiling->TileAt(0, 0));
   EXPECT_EQ(active_tiling->TileAt(0, 0), recycle_tiling->TileAt(0, 0));
 
   // Reset the active tiling. The recycle tiles should be released too.
   active_tiling->Reset();
   EXPECT_FALSE(active_tiling->TileAt(0, 0));
   EXPECT_FALSE(recycle_tiling->TileAt(0, 0));
 }
 
 }  // namespace
 }  // namespace cc