cc: Don't consider tiles at the layers raster_contents_scale incomplete

When PictureLayerImpl chooses a scale to raster at, we should accept
tiles at that scale as complete, and not try wait for tiles at some
other scale to be filled in. Such a tiling may not even exist.

R=enne, vmpstr
BUG=406433

Review URL: https://codereview.chromium.org/484363003

Cr-Commit-Position: refs/heads/master@{#291604}

cc/layers/picture_layer_impl.cc

@@ -298,7 +298,14 @@ void PictureLayerImpl::AppendQuads(
           gfx::Rect opaque_rect = iter->opaque_rect();
           opaque_rect.Intersect(geometry_rect);
 
-          if (iter->contents_scale() != ideal_contents_scale_ &&
+          // The raster_contents_scale_ is the best scale that the layer is
+          // trying to produce, even though it may not be ideal. Since that's
+          // the best the layer can promise in the future, consider those as
+          // complete. But if a tile is ideal scale, we don't want to consider
+          // it incomplete and trying to replace it with a tile at a worse
+          // scale.
+          if (iter->contents_scale() != raster_contents_scale_ &&
+              iter->contents_scale() != ideal_contents_scale_ &&
               geometry_rect.Intersects(scaled_viewport_for_tile_priority)) {
             append_quads_data->num_incomplete_tiles++;
           }

cc/layers/picture_layer_impl_unittest.cc

@@ -13,6 +13,7 @@
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/quads/draw_quad.h"
+#include "cc/quads/tile_draw_quad.h"
 #include "cc/test/begin_frame_args_test.h"
 #include "cc/test/fake_content_layer_client.h"
 #include "cc/test/fake_impl_proxy.h"
@@ -1550,6 +1551,156 @@ TEST_F(PictureLayerImplTest, TileOutsideOfViewportForTilePriorityNotRequired) {
   EXPECT_EQ(0u, data.num_incomplete_tiles);
 }
 
+TEST_F(PictureLayerImplTest, HighResTileIsComplete) {
+  base::TimeTicks time_ticks;
+  time_ticks += base::TimeDelta::FromMilliseconds(1);
+  host_impl_.SetCurrentBeginFrameArgs(
+      CreateBeginFrameArgsForTesting(time_ticks));
+
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(200, 200);
+
+  host_impl_.SetViewportSize(layer_bounds);
+
+  scoped_refptr<FakePicturePileImpl> pending_pile =
+      FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
+  SetupPendingTree(pending_pile);
+  ActivateTree();
+
+  // All high res tiles have resources.
+  active_layer_->set_fixed_tile_size(tile_size);
+  host_impl_.active_tree()->UpdateDrawProperties();
+  std::vector<Tile*> tiles =
+      active_layer_->tilings()->tiling_at(0)->AllTilesForTesting();
+  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(tiles);
+
+  MockOcclusionTracker<LayerImpl> occlusion_tracker;
+  scoped_ptr<RenderPass> render_pass = RenderPass::Create();
+  AppendQuadsData data;
+  active_layer_->WillDraw(DRAW_MODE_SOFTWARE, NULL);
+  active_layer_->AppendQuads(render_pass.get(), occlusion_tracker, &data);
+  active_layer_->DidDraw(NULL);
+
+  // All high res tiles drew, nothing was incomplete.
+  EXPECT_EQ(9u, render_pass->quad_list.size());
+  EXPECT_EQ(0u, data.num_missing_tiles);
+  EXPECT_EQ(0u, data.num_incomplete_tiles);
+}
+
+TEST_F(PictureLayerImplTest, LowResTileIsIncomplete) {
+  base::TimeTicks time_ticks;
+  time_ticks += base::TimeDelta::FromMilliseconds(1);
+  host_impl_.SetCurrentBeginFrameArgs(
+      CreateBeginFrameArgsForTesting(time_ticks));
+
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(200, 200);
+
+  host_impl_.SetViewportSize(layer_bounds);
+
+  scoped_refptr<FakePicturePileImpl> pending_pile =
+      FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
+  SetupPendingTree(pending_pile);
+  ActivateTree();
+
+  // All high res tiles have resources except one.
+  active_layer_->set_fixed_tile_size(tile_size);
+  host_impl_.active_tree()->UpdateDrawProperties();
+  std::vector<Tile*> high_tiles =
+      active_layer_->tilings()->tiling_at(0)->AllTilesForTesting();
+  high_tiles.erase(high_tiles.begin());
+  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(high_tiles);
+
+  // All low res tiles have resources.
+  std::vector<Tile*> low_tiles =
+      active_layer_->tilings()->tiling_at(1)->AllTilesForTesting();
+  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(low_tiles);
+
+  MockOcclusionTracker<LayerImpl> occlusion_tracker;
+  scoped_ptr<RenderPass> render_pass = RenderPass::Create();
+  AppendQuadsData data;
+  active_layer_->WillDraw(DRAW_MODE_SOFTWARE, NULL);
+  active_layer_->AppendQuads(render_pass.get(), occlusion_tracker, &data);
+  active_layer_->DidDraw(NULL);
+
+  // The missing high res tile was replaced by a low res tile.
+  EXPECT_EQ(9u, render_pass->quad_list.size());
+  EXPECT_EQ(0u, data.num_missing_tiles);
+  EXPECT_EQ(1u, data.num_incomplete_tiles);
+}
+
+TEST_F(PictureLayerImplTest,
+       HighResAndIdealResTileIsCompleteWhenRasterScaleIsNotIdeal) {
+  base::TimeTicks time_ticks;
+  time_ticks += base::TimeDelta::FromMilliseconds(1);
+  host_impl_.SetCurrentBeginFrameArgs(
+      CreateBeginFrameArgsForTesting(time_ticks));
+
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(200, 200);
+
+  host_impl_.SetViewportSize(layer_bounds);
+
+  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);
+
+  active_layer_->set_fixed_tile_size(tile_size);
+
+  active_layer_->draw_properties().visible_content_rect =
+      gfx::Rect(layer_bounds);
+  SetupDrawPropertiesAndUpdateTiles(active_layer_, 2.f, 1.f, 1.f, 1.f, false);
+
+  // One ideal tile exists, this will get used when drawing.
+  std::vector<Tile*> ideal_tiles =
+      active_layer_->HighResTiling()->AllTilesForTesting();
+  EXPECT_EQ(2.f, active_layer_->HighResTiling()->contents_scale());
+  while (ideal_tiles.size() > 1)
+    ideal_tiles.erase(ideal_tiles.begin() + 1);
+  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(
+      ideal_tiles);
+
+  // Due to layer scale throttling, the raster contents scale is changed to 1,
+  // while the ideal is still 2.
+  SetupDrawPropertiesAndUpdateTiles(active_layer_, 1.f, 1.f, 1.f, 1.f, false);
+  SetupDrawPropertiesAndUpdateTiles(active_layer_, 2.f, 1.f, 1.f, 1.f, false);
+
+  EXPECT_EQ(1.f, active_layer_->HighResTiling()->contents_scale());
+  EXPECT_EQ(1.f, active_layer_->raster_contents_scale());
+  EXPECT_EQ(2.f, active_layer_->ideal_contents_scale());
+
+  // Both tilings still exist.
+  EXPECT_EQ(2.f, active_layer_->tilings()->tiling_at(0)->contents_scale());
+  EXPECT_EQ(1.f, active_layer_->tilings()->tiling_at(1)->contents_scale());
+
+  // All high res tiles have resources.
+  std::vector<Tile*> high_tiles =
+      active_layer_->HighResTiling()->AllTilesForTesting();
+  host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(high_tiles);
+
+  MockOcclusionTracker<LayerImpl> occlusion_tracker;
+  scoped_ptr<RenderPass> render_pass = RenderPass::Create();
+  AppendQuadsData data;
+  active_layer_->WillDraw(DRAW_MODE_SOFTWARE, NULL);
+  active_layer_->AppendQuads(render_pass.get(), occlusion_tracker, &data);
+  active_layer_->DidDraw(NULL);
+
+  // All high res tiles drew, and the one ideal res tile drew.
+  ASSERT_GT(render_pass->quad_list.size(), 9u);
+  EXPECT_EQ(gfx::SizeF(99.f, 99.f),
+            TileDrawQuad::MaterialCast(render_pass->quad_list[0])
+                ->tex_coord_rect.size());
+  EXPECT_EQ(gfx::SizeF(49.5f, 49.5f),
+            TileDrawQuad::MaterialCast(render_pass->quad_list[1])
+                ->tex_coord_rect.size());
+
+  // Neither the high res nor the ideal tiles were considered as incomplete.
+  EXPECT_EQ(0u, data.num_missing_tiles);
+  EXPECT_EQ(0u, data.num_incomplete_tiles);
+}
+
 TEST_F(PictureLayerImplTest, HighResRequiredWhenUnsharedActiveAllReady) {
   gfx::Size layer_bounds(400, 400);
   gfx::Size tile_size(100, 100);

cc/test/fake_picture_layer_impl.h

@@ -75,6 +75,9 @@ class FakePictureLayerImpl : public PictureLayerImpl {
   float raster_page_scale() const { return raster_page_scale_; }
   void set_raster_page_scale(float scale) { raster_page_scale_ = scale; }
 
+  float ideal_contents_scale() const { return ideal_contents_scale_; }
+  float raster_contents_scale() const { return raster_contents_scale_; }
+
   PictureLayerTiling* HighResTiling() const;
   PictureLayerTiling* LowResTiling() const;
   size_t num_tilings() const { return tilings_->num_tilings(); }