cc: Consider resolution when checking HigherPriorityTree.

When we skip shared tiles in raster iterators, we need to ensure
that we consider resolution as a factor, since the twin will not be
returning tiles if they are of non-ideal resolution (so we shouldn't
be skipping the tile if the twin has higher, but non ideal, priority).

BUG=477136
R=sunnyps, vmiura

Review URL: https://codereview.chromium.org/1064743003

Cr-Commit-Position: refs/heads/master@{#325346}

cc/resources/raster_tile_priority_queue_all.cc

@@ -86,12 +86,21 @@ WhichTree HigherPriorityTree(TreePriority tree_priority,
                              const TilingSetRasterQueueAll* active_queue,
                              const TilingSetRasterQueueAll* pending_queue,
                              const Tile* shared_tile) {
+  // In cases when we're given an active tile with a non ideal active resolution
+  // (or pending tile with non ideal pending resolution), we should return the
+  // other tree. The reason for this is that tiling set iterators will not
+  // return non ideal tiles and the only way we get here is if we're skipping
+  // twin tiles, but since it's non-ideal on the twin, we shouldn't skip it.
+  // TODO(vmpstr): Remove when tiles aren't shared.
+  const Tile* active_tile = shared_tile ? shared_tile : active_queue->Top();
+  const Tile* pending_tile = shared_tile ? shared_tile : pending_queue->Top();
+  if (active_tile->priority(ACTIVE_TREE).resolution == NON_IDEAL_RESOLUTION)
+    return PENDING_TREE;
+  if (pending_tile->priority(PENDING_TREE).resolution == NON_IDEAL_RESOLUTION)
+    return ACTIVE_TREE;
+
   switch (tree_priority) {
     case SMOOTHNESS_TAKES_PRIORITY: {
-      const Tile* active_tile = shared_tile ? shared_tile : active_queue->Top();
-      const Tile* pending_tile =
-          shared_tile ? shared_tile : pending_queue->Top();
-
       const TilePriority& active_priority = active_tile->priority(ACTIVE_TREE);
       const TilePriority& pending_priority =
           pending_tile->priority(PENDING_TREE);
@@ -108,10 +117,6 @@ WhichTree HigherPriorityTree(TreePriority tree_priority,
     case NEW_CONTENT_TAKES_PRIORITY:
       return PENDING_TREE;
     case SAME_PRIORITY_FOR_BOTH_TREES: {
-      const Tile* active_tile = shared_tile ? shared_tile : active_queue->Top();
-      const Tile* pending_tile =
-          shared_tile ? shared_tile : pending_queue->Top();
-
       const TilePriority& active_priority = active_tile->priority(ACTIVE_TREE);
       const TilePriority& pending_priority =
           pending_tile->priority(PENDING_TREE);

cc/resources/tile_manager_unittest.cc

@@ -426,6 +426,64 @@ TEST_F(TileManagerTilePriorityQueueTest, RasterTilePriorityQueue) {
   EXPECT_NE(new_content_tiles, required_for_draw_tiles);
 }
 
+TEST_F(TileManagerTilePriorityQueueTest,
+       RasterTilePriorityQueueHighNonIdealTilings) {
+  const gfx::Size layer_bounds(1000, 1000);
+  const gfx::Size viewport(800, 800);
+  host_impl_.SetViewportSize(viewport);
+  SetupDefaultTrees(layer_bounds);
+
+  pending_layer_->tilings()->AddTiling(1.5f, pending_layer_->raster_source());
+  active_layer_->tilings()->AddTiling(1.5f, active_layer_->raster_source());
+
+  pending_layer_->tilings()->UpdateTilePriorities(gfx::Rect(viewport), 1.f, 5.0,
+                                                  Occlusion(), true);
+  active_layer_->tilings()->UpdateTilePriorities(gfx::Rect(viewport), 1.f, 5.0,
+                                                 Occlusion(), true);
+
+  std::set<Tile*> all_expected_tiles;
+  for (size_t i = 0; i < pending_layer_->num_tilings(); ++i) {
+    PictureLayerTiling* tiling = pending_layer_->tilings()->tiling_at(i);
+    tiling->CreateAllTilesForTesting();
+    if (tiling->contents_scale() == 1.f) {
+      tiling->set_resolution(HIGH_RESOLUTION);
+      const auto& all_tiles = tiling->AllTilesForTesting();
+      all_expected_tiles.insert(all_tiles.begin(), all_tiles.end());
+    } else {
+      tiling->set_resolution(NON_IDEAL_RESOLUTION);
+    }
+  }
+
+  for (size_t i = 0; i < active_layer_->num_tilings(); ++i) {
+    PictureLayerTiling* tiling = active_layer_->tilings()->tiling_at(i);
+    tiling->CreateAllTilesForTesting();
+    if (tiling->contents_scale() == 1.5f) {
+      tiling->set_resolution(HIGH_RESOLUTION);
+      const auto& all_tiles = tiling->AllTilesForTesting();
+      all_expected_tiles.insert(all_tiles.begin(), all_tiles.end());
+    } else {
+      tiling->set_resolution(NON_IDEAL_RESOLUTION);
+    }
+  }
+
+  scoped_ptr<RasterTilePriorityQueue> queue(host_impl_.BuildRasterQueue(
+      SMOOTHNESS_TAKES_PRIORITY, RasterTilePriorityQueue::Type::ALL));
+  EXPECT_FALSE(queue->IsEmpty());
+
+  size_t tile_count = 0;
+  std::set<Tile*> all_actual_tiles;
+  while (!queue->IsEmpty()) {
+    EXPECT_TRUE(queue->Top());
+    all_actual_tiles.insert(queue->Top());
+    ++tile_count;
+    queue->Pop();
+  }
+
+  EXPECT_EQ(tile_count, all_actual_tiles.size());
+  EXPECT_EQ(all_expected_tiles.size(), all_actual_tiles.size());
+  EXPECT_EQ(all_expected_tiles, all_actual_tiles);
+}
+
 TEST_F(TileManagerTilePriorityQueueTest, RasterTilePriorityQueueInvalidation) {
   const gfx::Size layer_bounds(1000, 1000);
   host_impl_.SetViewportSize(gfx::Size(500, 500));