Re-land: cc: Examine layers to determine if we're ready to activate.

This introduces a new mechanism for determining when
we're ready to activate the pending tree. The tile
priority is still used to determine when it's worth
waking up the compositor thread and evaluating if
we can activate. However, the actual check that
determines if we're ready to activate doesn't rely
on the state of scheduled raster tasks but is a
synchronous call on each layer.

The result is a pending tree activation mechanism that
is much easier to debug and validate for correctness,
while still providing the performance benefits of the
old mechanism by taking the "required to activate" field
of the tile priority into account when scheduling tasks.
 
BUG=375206
TEST=cc_unittests --gtest_filter=PictureLayerImplTest.AllTilesRequiredForActivationAreReadyToDraw

Review URL: https://codereview.chromium.org/287643004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273040 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 269 insertions, 149 deletions

diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 99642cb..c97ae12 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -188,7 +188,7 @@ class CC_EXPORT LayerImpl : public LayerAnimationValueObserver,
   virtual RenderPass::Id NextContributingRenderPassId(RenderPass::Id id) const;
 
   virtual void UpdateTilePriorities() {}
-  virtual void NotifyTileInitialized(const Tile* tile) {}
+  virtual void NotifyTileStateChanged(const Tile* tile) {}
 
   virtual ScrollbarLayerImplBase* ToScrollbarLayer();
 
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 250dafa..76ab5bb6 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -233,7 +233,8 @@ void PictureLayerImpl::AppendQuads(QuadSink* quad_sink,
   // unused can be considered for removal.
   std::vector<PictureLayerTiling*> seen_tilings;
 
-  bool had_checkerboard_quads = false;
+  size_t missing_tile_count = 0u;
+  size_t on_demand_missing_tile_count = 0u;
   for (PictureLayerTilingSet::CoverageIterator iter(
       tilings_.get(), contents_scale_x(), rect, ideal_contents_scale_);
        iter;
@@ -247,8 +248,75 @@ void PictureLayerImpl::AppendQuads(QuadSink* quad_sink,
     append_quads_data->visible_content_area +=
         visible_geometry_rect.width() * visible_geometry_rect.height();
 
-    if (!*iter || !iter->IsReadyToDraw()) {
-      had_checkerboard_quads = true;
+    scoped_ptr<DrawQuad> draw_quad;
+    if (*iter && iter->IsReadyToDraw()) {
+      const ManagedTileState::TileVersion& tile_version =
+          iter->GetTileVersionForDrawing();
+      switch (tile_version.mode()) {
+        case ManagedTileState::TileVersion::RESOURCE_MODE: {
+          gfx::RectF texture_rect = iter.texture_rect();
+          gfx::Rect opaque_rect = iter->opaque_rect();
+          opaque_rect.Intersect(geometry_rect);
+
+          if (iter->contents_scale() != ideal_contents_scale_)
+            append_quads_data->had_incomplete_tile = true;
+
+          scoped_ptr<TileDrawQuad> quad = TileDrawQuad::Create();
+          quad->SetNew(shared_quad_state,
+                       geometry_rect,
+                       opaque_rect,
+                       visible_geometry_rect,
+                       tile_version.get_resource_id(),
+                       texture_rect,
+                       iter.texture_size(),
+                       tile_version.contents_swizzled());
+          draw_quad = quad.PassAs<DrawQuad>();
+          break;
+        }
+        case ManagedTileState::TileVersion::PICTURE_PILE_MODE: {
+          if (!layer_tree_impl()
+                   ->GetRendererCapabilities()
+                   .allow_rasterize_on_demand) {
+            ++on_demand_missing_tile_count;
+            break;
+          }
+
+          gfx::RectF texture_rect = iter.texture_rect();
+          gfx::Rect opaque_rect = iter->opaque_rect();
+          opaque_rect.Intersect(geometry_rect);
+
+          ResourceProvider* resource_provider =
+              layer_tree_impl()->resource_provider();
+          ResourceFormat format =
+              resource_provider->memory_efficient_texture_format();
+          scoped_ptr<PictureDrawQuad> quad = PictureDrawQuad::Create();
+          quad->SetNew(shared_quad_state,
+                       geometry_rect,
+                       opaque_rect,
+                       visible_geometry_rect,
+                       texture_rect,
+                       iter.texture_size(),
+                       format,
+                       iter->content_rect(),
+                       iter->contents_scale(),
+                       pile_);
+          draw_quad = quad.PassAs<DrawQuad>();
+          break;
+        }
+        case ManagedTileState::TileVersion::SOLID_COLOR_MODE: {
+          scoped_ptr<SolidColorDrawQuad> quad = SolidColorDrawQuad::Create();
+          quad->SetNew(shared_quad_state,
+                       geometry_rect,
+                       visible_geometry_rect,
+                       tile_version.get_solid_color(),
+                       false);
+          draw_quad = quad.PassAs<DrawQuad>();
+          break;
+        }
+      }
+    }
+
+    if (!draw_quad) {
       if (draw_checkerboard_for_missing_tiles()) {
         scoped_ptr<CheckerboardDrawQuad> quad = CheckerboardDrawQuad::Create();
         SkColor color = DebugColors::DefaultCheckerboardColor();
@@ -270,69 +338,10 @@ void PictureLayerImpl::AppendQuads(QuadSink* quad_sink,
       append_quads_data->had_incomplete_tile = true;
       append_quads_data->approximated_visible_content_area +=
           visible_geometry_rect.width() * visible_geometry_rect.height();
+      ++missing_tile_count;
       continue;
     }
 
-    const ManagedTileState::TileVersion& tile_version =
-        iter->GetTileVersionForDrawing();
-    scoped_ptr<DrawQuad> draw_quad;
-    switch (tile_version.mode()) {
-      case ManagedTileState::TileVersion::RESOURCE_MODE: {
-        gfx::RectF texture_rect = iter.texture_rect();
-        gfx::Rect opaque_rect = iter->opaque_rect();
-        opaque_rect.Intersect(geometry_rect);
-
-        if (iter->contents_scale() != ideal_contents_scale_)
-          append_quads_data->had_incomplete_tile = true;
-
-        scoped_ptr<TileDrawQuad> quad = TileDrawQuad::Create();
-        quad->SetNew(shared_quad_state,
-                     geometry_rect,
-                     opaque_rect,
-                     visible_geometry_rect,
-                     tile_version.get_resource_id(),
-                     texture_rect,
-                     iter.texture_size(),
-                     tile_version.contents_swizzled());
-        draw_quad = quad.PassAs<DrawQuad>();
-        break;
-      }
-      case ManagedTileState::TileVersion::PICTURE_PILE_MODE: {
-        gfx::RectF texture_rect = iter.texture_rect();
-        gfx::Rect opaque_rect = iter->opaque_rect();
-        opaque_rect.Intersect(geometry_rect);
-
-        ResourceProvider* resource_provider =
-            layer_tree_impl()->resource_provider();
-        ResourceFormat format =
-            resource_provider->memory_efficient_texture_format();
-        scoped_ptr<PictureDrawQuad> quad = PictureDrawQuad::Create();
-        quad->SetNew(shared_quad_state,
-                     geometry_rect,
-                     opaque_rect,
-                     visible_geometry_rect,
-                     texture_rect,
-                     iter.texture_size(),
-                     format,
-                     iter->content_rect(),
-                     iter->contents_scale(),
-                     pile_);
-        draw_quad = quad.PassAs<DrawQuad>();
-        break;
-      }
-      case ManagedTileState::TileVersion::SOLID_COLOR_MODE: {
-        scoped_ptr<SolidColorDrawQuad> quad = SolidColorDrawQuad::Create();
-        quad->SetNew(shared_quad_state,
-                     geometry_rect,
-                     visible_geometry_rect,
-                     tile_version.get_solid_color(),
-                     false);
-        draw_quad = quad.PassAs<DrawQuad>();
-        break;
-      }
-    }
-
-    DCHECK(draw_quad);
     quad_sink->Append(draw_quad.Pass());
 
     if (iter->priority(ACTIVE_TREE).resolution != HIGH_RESOLUTION) {
@@ -344,10 +353,14 @@ void PictureLayerImpl::AppendQuads(QuadSink* quad_sink,
       seen_tilings.push_back(iter.CurrentTiling());
   }
 
-  if (had_checkerboard_quads) {
-    TRACE_EVENT_INSTANT0("cc",
+  if (missing_tile_count) {
+    TRACE_EVENT_INSTANT2("cc",
                          "PictureLayerImpl::AppendQuads checkerboard",
-                         TRACE_EVENT_SCOPE_THREAD);
+                         TRACE_EVENT_SCOPE_THREAD,
+                         "missing_tile_count",
+                         missing_tile_count,
+                         "on_demand_missing_tile_count",
+                         on_demand_missing_tile_count);
   }
 
   // Aggressively remove any tilings that are not seen to save memory. Note
@@ -429,7 +442,7 @@ void PictureLayerImpl::UpdateTilePriorities() {
   layer_tree_impl()->DidModifyTilePriorities();
 }
 
-void PictureLayerImpl::NotifyTileInitialized(const Tile* tile) {
+void PictureLayerImpl::NotifyTileStateChanged(const Tile* tile) {
   if (layer_tree_impl()->IsActiveTree()) {
     gfx::RectF layer_damage_rect =
         gfx::ScaleRect(tile->content_rect(), 1.f / tile->contents_scale());
@@ -1354,6 +1367,37 @@ bool PictureLayerImpl::IsOnActiveOrPendingTree() const {
   return !layer_tree_impl()->IsRecycleTree();
 }
 
+bool PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw() const {
+  if (!layer_tree_impl()->IsPendingTree())
+    return true;
+
+  if (!tilings_)
+    return true;
+
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    PictureLayerTiling* tiling = tilings_->tiling_at(i);
+    if (tiling->resolution() != HIGH_RESOLUTION &&
+        tiling->resolution() != LOW_RESOLUTION)
+      continue;
+
+    gfx::Rect rect(visible_content_rect());
+    for (PictureLayerTiling::CoverageIterator iter(
+             tiling, contents_scale_x(), rect);
+         iter;
+         ++iter) {
+      const Tile* tile = *iter;
+      // A null tile (i.e. missing recording) can just be skipped.
+      if (!tile)
+        continue;
+
+      if (tile->required_for_activation() && !tile->IsReadyToDraw())
+        return false;
+    }
+  }
+
+  return true;
+}
+
 PictureLayerImpl::LayerRasterTileIterator::LayerRasterTileIterator()
     : layer_(NULL) {}
 
diff --git a/cc/layers/picture_layer_impl.h b/cc/layers/picture_layer_impl.h
index afd96aa..9609ccf 100644
--- a/cc/layers/picture_layer_impl.h
+++ b/cc/layers/picture_layer_impl.h
@@ -92,7 +92,7 @@ class CC_EXPORT PictureLayerImpl
   virtual void AppendQuads(QuadSink* quad_sink,
                            AppendQuadsData* append_quads_data) OVERRIDE;
   virtual void UpdateTilePriorities() OVERRIDE;
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE;
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE;
   virtual void DidBecomeActive() OVERRIDE;
   virtual void DidBeginTracing() OVERRIDE;
   virtual void ReleaseResources() OVERRIDE;
@@ -136,6 +136,7 @@ class CC_EXPORT PictureLayerImpl
   PictureLayerImpl* GetTwinLayer() { return twin_layer_; }
   WhichTree GetTree() const;
   bool IsOnActiveOrPendingTree() const;
+  bool AllTilesRequiredForActivationAreReadyToDraw() const;
 
  protected:
   friend class LayerRasterTileIterator;
diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index d919298..64454ae 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -2391,5 +2391,61 @@ TEST_F(PictureLayerImplTest, RasterScaleChangeWithoutAnimation) {
   EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 1.f);
 }
 
+TEST_F(PictureLayerImplTest, LowResReadyToDrawNotEnoughToActivate) {
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(1000, 1000);
+
+  SetupDefaultTreesWithFixedTileSize(layer_bounds, tile_size);
+
+  // Make sure some tiles are not shared.
+  pending_layer_->set_invalidation(gfx::Rect(gfx::Point(50, 50), tile_size));
+
+  CreateHighLowResAndSetAllTilesVisible();
+  active_layer_->SetAllTilesReady();
+  pending_layer_->MarkVisibleResourcesAsRequired();
+
+  // All pending layer tiles required are not ready.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize all low-res tiles.
+  pending_layer_->SetAllTilesReadyInTiling(pending_layer_->LowResTiling());
+
+  // Low-res tiles should not be enough.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize remaining tiles.
+  pending_layer_->SetAllTilesReady();
+
+  EXPECT_TRUE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+}
+
+TEST_F(PictureLayerImplTest, HighResReadyToDrawNotEnoughToActivate) {
+  gfx::Size tile_size(100, 100);
+  gfx::Size layer_bounds(1000, 1000);
+
+  SetupDefaultTreesWithFixedTileSize(layer_bounds, tile_size);
+
+  // Make sure some tiles are not shared.
+  pending_layer_->set_invalidation(gfx::Rect(gfx::Point(50, 50), tile_size));
+
+  CreateHighLowResAndSetAllTilesVisible();
+  active_layer_->SetAllTilesReady();
+  pending_layer_->MarkVisibleResourcesAsRequired();
+
+  // All pending layer tiles required are not ready.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize all high-res tiles.
+  pending_layer_->SetAllTilesReadyInTiling(pending_layer_->HighResTiling());
+
+  // High-res tiles should not be enough.
+  EXPECT_FALSE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+
+  // Initialize remaining tiles.
+  pending_layer_->SetAllTilesReady();
+
+  EXPECT_TRUE(pending_layer_->AllTilesRequiredForActivationAreReadyToDraw());
+}
+
 }  // namespace
 }  // namespace cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 2b3e652..416c4e6 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -365,24 +365,25 @@ scoped_ptr<base::Value> RasterTaskCompletionStatsAsValue(
 // static
 scoped_ptr<TileManager> TileManager::Create(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation) {
   return make_scoped_ptr(new TileManager(client,
+                                         task_runner,
                                          resource_pool,
                                          rasterizer,
-                                         use_rasterize_on_demand,
                                          rendering_stats_instrumentation));
 }
 
 TileManager::TileManager(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
     : client_(client),
+      task_runner_(task_runner),
       resource_pool_(resource_pool),
       rasterizer_(rasterizer),
       prioritized_tiles_dirty_(false),
@@ -396,7 +397,8 @@ TileManager::TileManager(
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       did_initialize_visible_tile_(false),
       did_check_for_completed_tasks_since_last_schedule_tasks_(true),
-      use_rasterize_on_demand_(use_rasterize_on_demand) {
+      check_if_ready_to_activate_pending_(false),
+      weak_ptr_factory_(this) {
   rasterizer_->SetClient(this);
 }
 
@@ -528,12 +530,14 @@ void TileManager::DidFinishRunningTasks() {
       // If we can't raster on demand, give up early (and don't activate).
       if (!allow_rasterize_on_demand)
         return;
-      if (use_rasterize_on_demand_)
-        tile_version.set_rasterize_on_demand();
+
+      tile_version.set_rasterize_on_demand();
+      client_->NotifyTileStateChanged(tile);
     }
   }
 
-  client_->NotifyReadyToActivate();
+  DCHECK(IsReadyToActivate());
+  ScheduleCheckIfReadyToActivate();
 }
 
 void TileManager::DidFinishRunningTasksRequiredForActivation() {
@@ -545,7 +549,7 @@ void TileManager::DidFinishRunningTasksRequiredForActivation() {
   if (!all_tiles_required_for_activation_have_memory_)
     return;
 
-  client_->NotifyReadyToActivate();
+  ScheduleCheckIfReadyToActivate();
 }
 
 void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
@@ -664,7 +668,7 @@ void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
     // can visit it.
     if (mts.bin == NEVER_BIN &&
         !mts.tile_versions[mts.raster_mode].raster_task_) {
-      FreeResourcesForTile(tile);
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
       continue;
     }
 
@@ -853,7 +857,7 @@ void TileManager::AssignGpuMemoryToTiles(
 
     // If the tile is not needed, free it up.
     if (mts.bin == NEVER_BIN) {
-      FreeResourcesForTile(tile);
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
       continue;
     }
 
@@ -895,14 +899,19 @@ void TileManager::AssignGpuMemoryToTiles(
 
     // Tile is OOM.
     if (tile_bytes > tile_bytes_left || tile_resources > resources_left) {
+      bool was_ready_to_draw = tile->IsReadyToDraw();
+
       FreeResourcesForTile(tile);
 
       // This tile was already on screen and now its resources have been
       // released. In order to prevent checkerboarding, set this tile as
       // rasterize on demand immediately.
-      if (mts.visible_and_ready_to_draw && use_rasterize_on_demand_)
+      if (mts.visible_and_ready_to_draw)
         tile_version.set_rasterize_on_demand();
 
+      if (was_ready_to_draw)
+        client_->NotifyTileStateChanged(tile);
+
       oomed_soft = true;
       if (tile_uses_hard_limit) {
         oomed_hard = true;
@@ -997,6 +1006,14 @@ void TileManager::FreeUnusedResourcesForTile(Tile* tile) {
   }
 }
 
+void TileManager::FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(
+    Tile* tile) {
+  bool was_ready_to_draw = tile->IsReadyToDraw();
+  FreeResourcesForTile(tile);
+  if (was_ready_to_draw)
+    client_->NotifyTileStateChanged(tile);
+}
+
 void TileManager::ScheduleTasks(
     const TileVector& tiles_that_need_to_be_rasterized) {
   TRACE_EVENT1("cc",
@@ -1189,11 +1206,11 @@ void TileManager::OnRasterTaskCompleted(
     ++resources_releasable_;
   }
 
-  client_->NotifyTileInitialized(tile);
-
   FreeUnusedResourcesForTile(tile);
   if (tile->priority(ACTIVE_TREE).distance_to_visible == 0.f)
     did_initialize_visible_tile_ = true;
+
+  client_->NotifyTileStateChanged(tile);
 }
 
 scoped_refptr<Tile> TileManager::CreateTile(PicturePileImpl* picture_pile,
@@ -1627,4 +1644,38 @@ void TileManager::SetRasterizerForTesting(Rasterizer* rasterizer) {
   rasterizer_->SetClient(this);
 }
 
+bool TileManager::IsReadyToActivate() const {
+  for (std::vector<PictureLayerImpl*>::const_iterator it = layers_.begin();
+       it != layers_.end();
+       ++it) {
+    if (!(*it)->AllTilesRequiredForActivationAreReadyToDraw())
+      return false;
+  }
+
+  return true;
+}
+
+void TileManager::ScheduleCheckIfReadyToActivate() {
+  if (check_if_ready_to_activate_pending_)
+    return;
+
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&TileManager::CheckIfReadyToActivate,
+                                    weak_ptr_factory_.GetWeakPtr()));
+  check_if_ready_to_activate_pending_ = true;
+}
+
+void TileManager::CheckIfReadyToActivate() {
+  TRACE_EVENT0("cc", "TileManager::CheckIfReadyToActivate");
+
+  DCHECK(check_if_ready_to_activate_pending_);
+  check_if_ready_to_activate_pending_ = false;
+
+  rasterizer_->CheckForCompletedTasks();
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
+
+  if (IsReadyToActivate())
+    client_->NotifyReadyToActivate();
+}
+
 }  // namespace cc
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index cdc7d1e..0881e6f 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -30,8 +30,15 @@ class ResourceProvider;
 
 class CC_EXPORT TileManagerClient {
  public:
+  // Called when all tiles marked as required for activation are ready to draw.
   virtual void NotifyReadyToActivate() = 0;
-  virtual void NotifyTileInitialized(const Tile* tile) = 0;
+
+  // Called when the visible representation of a tile might have changed. Some
+  // examples are:
+  // - Tile version initialized.
+  // - Tile resources freed.
+  // - Tile marked for on-demand raster.
+  virtual void NotifyTileStateChanged(const Tile* tile) = 0;
 
  protected:
   virtual ~TileManagerClient() {}
@@ -154,9 +161,9 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   static scoped_ptr<TileManager> Create(
       TileManagerClient* client,
+      base::SequencedTaskRunner* task_runner,
       ResourcePool* resource_pool,
       Rasterizer* rasterizer,
-      bool use_rasterize_on_demand,
       RenderingStatsInstrumentation* rendering_stats_instrumentation);
   virtual ~TileManager();
 
@@ -228,9 +235,9 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
  protected:
   TileManager(TileManagerClient* client,
+              base::SequencedTaskRunner* task_runner,
               ResourcePool* resource_pool,
               Rasterizer* rasterizer,
-              bool use_rasterize_on_demand,
               RenderingStatsInstrumentation* rendering_stats_instrumentation);
 
   // Methods called by Tile
@@ -276,6 +283,7 @@ class CC_EXPORT TileManager : public RasterizerClient,
   void FreeResourceForTile(Tile* tile, RasterMode mode);
   void FreeResourcesForTile(Tile* tile);
   void FreeUnusedResourcesForTile(Tile* tile);
+  void FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(Tile* tile);
   scoped_refptr<ImageDecodeTask> CreateImageDecodeTask(Tile* tile,
                                                        SkPixelRef* pixel_ref);
   scoped_refptr<RasterTask> CreateRasterTask(Tile* tile);
@@ -283,7 +291,12 @@ class CC_EXPORT TileManager : public RasterizerClient,
   void UpdatePrioritizedTileSetIfNeeded();
   void CleanUpLayers();
 
+  bool IsReadyToActivate() const;
+  void ScheduleCheckIfReadyToActivate();
+  void CheckIfReadyToActivate();
+
   TileManagerClient* client_;
+  scoped_refptr<base::SequencedTaskRunner> task_runner_;
   ResourcePool* resource_pool_;
   Rasterizer* rasterizer_;
   GlobalStateThatImpactsTilePriority global_state_;
@@ -323,8 +336,6 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   std::vector<Tile*> released_tiles_;
 
-  bool use_rasterize_on_demand_;
-
   ResourceFormat resource_format_;
 
   // Queue used when scheduling raster tasks.
@@ -334,6 +345,10 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   std::vector<PictureLayerImpl*> layers_;
 
+  bool check_if_ready_to_activate_pending_;
+
+  base::WeakPtrFactory<TileManager> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
diff --git a/cc/resources/tile_manager_perftest.cc b/cc/resources/tile_manager_perftest.cc
index 22e7c66..c7fa68f 100644
--- a/cc/resources/tile_manager_perftest.cc
+++ b/cc/resources/tile_manager_perftest.cc
@@ -293,7 +293,7 @@ class TileManagerPerfTest : public testing::Test, public TileManagerClient {
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileManager* tile_manager() { return host_impl_.tile_manager(); }
 
diff --git a/cc/resources/tile_manager_unittest.cc b/cc/resources/tile_manager_unittest.cc
index 5a1837f..ce54d38 100644
--- a/cc/resources/tile_manager_unittest.cc
+++ b/cc/resources/tile_manager_unittest.cc
@@ -32,8 +32,7 @@ class TileManagerTest : public testing::TestWithParam<bool>,
 
   void Initialize(int max_tiles,
                   TileMemoryLimitPolicy memory_limit_policy,
-                  TreePriority tree_priority,
-                  bool allow_on_demand_raster = true) {
+                  TreePriority tree_priority) {
     output_surface_ = FakeOutputSurface::Create3d();
     CHECK(output_surface_->BindToClient(&output_surface_client_));
 
@@ -43,8 +42,8 @@ class TileManagerTest : public testing::TestWithParam<bool>,
         false);
     resource_pool_ = ResourcePool::Create(
         resource_provider_.get(), GL_TEXTURE_2D, RGBA_8888);
-    tile_manager_ = make_scoped_ptr(new FakeTileManager(
-        this, resource_pool_.get(), allow_on_demand_raster));
+    tile_manager_ =
+        make_scoped_ptr(new FakeTileManager(this, resource_pool_.get()));
 
     memory_limit_policy_ = memory_limit_policy;
     max_tiles_ = max_tiles;
@@ -85,7 +84,7 @@ class TileManagerTest : public testing::TestWithParam<bool>,
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileVector CreateTilesWithSize(int count,
                                  TilePriority active_priority,
@@ -614,40 +613,6 @@ TEST_P(TileManagerTest, RespectMemoryLimit) {
   EXPECT_LE(memory_allocated_bytes, global_state_.hard_memory_limit_in_bytes);
 }
 
-TEST_P(TileManagerTest, AllowRasterizeOnDemand) {
-  // Not enough memory to initialize tiles required for activation.
-  Initialize(0, ALLOW_ANYTHING, SAME_PRIORITY_FOR_BOTH_TREES);
-  TileVector tiles =
-      CreateTiles(2, TilePriority(), TilePriorityRequiredForActivation());
-
-  tile_manager()->AssignMemoryToTiles(global_state_);
-
-  // This should make required tiles ready to draw by marking them as
-  // required tiles for on-demand raster.
-  tile_manager()->DidFinishRunningTasksForTesting();
-
-  EXPECT_TRUE(ready_to_activate());
-  for (TileVector::iterator it = tiles.begin(); it != tiles.end(); ++it)
-    EXPECT_TRUE((*it)->IsReadyToDraw());
-}
-
-TEST_P(TileManagerTest, PreventRasterizeOnDemand) {
-  // Not enough memory to initialize tiles required for activation.
-  Initialize(0, ALLOW_ANYTHING, SAME_PRIORITY_FOR_BOTH_TREES, false);
-  TileVector tiles =
-      CreateTiles(2, TilePriority(), TilePriorityRequiredForActivation());
-
-  tile_manager()->AssignMemoryToTiles(global_state_);
-
-  // This should make required tiles ready to draw by marking them as
-  // required tiles for on-demand raster.
-  tile_manager()->DidFinishRunningTasksForTesting();
-
-  EXPECT_TRUE(ready_to_activate());
-  for (TileVector::iterator it = tiles.begin(); it != tiles.end(); ++it)
-    EXPECT_FALSE((*it)->IsReadyToDraw());
-}
-
 // If true, the max tile limit should be applied as bytes; if false,
 // as num_resources_limit.
 INSTANTIATE_TEST_CASE_P(TileManagerTests,
@@ -754,7 +719,7 @@ class TileManagerTileIteratorTest : public testing::Test,
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileManager* tile_manager() { return host_impl_.tile_manager(); }
 
diff --git a/cc/test/fake_tile_manager.cc b/cc/test/fake_tile_manager.cc
index 496baea..1fc2e43 100644
--- a/cc/test/fake_tile_manager.cc
+++ b/cc/test/fake_tile_manager.cc
@@ -63,26 +63,17 @@ base::LazyInstance<FakeRasterizerImpl> g_fake_rasterizer =
 
 FakeTileManager::FakeTileManager(TileManagerClient* client)
     : TileManager(client,
+                  base::MessageLoopProxy::current(),
                   NULL,
                   g_fake_rasterizer.Pointer(),
-                  true,
                   NULL) {}
 
 FakeTileManager::FakeTileManager(TileManagerClient* client,
                                  ResourcePool* resource_pool)
     : TileManager(client,
+                  base::MessageLoopProxy::current(),
                   resource_pool,
                   g_fake_rasterizer.Pointer(),
-                  true,
-                  NULL) {}
-
-FakeTileManager::FakeTileManager(TileManagerClient* client,
-                                 ResourcePool* resource_pool,
-                                 bool allow_on_demand_raster)
-    : TileManager(client,
-                  resource_pool,
-                  g_fake_rasterizer.Pointer(),
-                  allow_on_demand_raster,
                   NULL) {}
 
 FakeTileManager::~FakeTileManager() {}
diff --git a/cc/test/fake_tile_manager.h b/cc/test/fake_tile_manager.h
index c5c7a25..05dbe61 100644
--- a/cc/test/fake_tile_manager.h
+++ b/cc/test/fake_tile_manager.h
@@ -16,9 +16,6 @@ class FakeTileManager : public TileManager {
  public:
   explicit FakeTileManager(TileManagerClient* client);
   FakeTileManager(TileManagerClient* client, ResourcePool* resource_pool);
-  FakeTileManager(TileManagerClient* client,
-                  ResourcePool* resource_pool,
-                  bool allow_on_demand_raster);
   virtual ~FakeTileManager();
 
   bool HasBeenAssignedMemory(Tile* tile);
diff --git a/cc/test/fake_tile_manager_client.h b/cc/test/fake_tile_manager_client.h
index dd368b9..7faa30e 100644
--- a/cc/test/fake_tile_manager_client.h
+++ b/cc/test/fake_tile_manager_client.h
@@ -15,7 +15,7 @@ class FakeTileManagerClient : public TileManagerClient {
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE {}
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 };
 
 }  // namespace cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 219ea89..803c414 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1240,21 +1240,21 @@ void LayerTreeHostImpl::NotifyReadyToActivate() {
   client_->NotifyReadyToActivate();
 }
 
-void LayerTreeHostImpl::NotifyTileInitialized(const Tile* tile) {
-  TRACE_EVENT0("cc", "LayerTreeHostImpl::NotifyTileInitialized");
+void LayerTreeHostImpl::NotifyTileStateChanged(const Tile* tile) {
+  TRACE_EVENT0("cc", "LayerTreeHostImpl::NotifyTileStateChanged");
 
   if (active_tree_) {
     LayerImpl* layer_impl =
         active_tree_->FindActiveTreeLayerById(tile->layer_id());
     if (layer_impl)
-      layer_impl->NotifyTileInitialized(tile);
+      layer_impl->NotifyTileStateChanged(tile);
   }
 
   if (pending_tree_) {
     LayerImpl* layer_impl =
         pending_tree_->FindPendingTreeLayerById(tile->layer_id());
     if (layer_impl)
-      layer_impl->NotifyTileInitialized(tile);
+      layer_impl->NotifyTileStateChanged(tile);
   }
 }
 
@@ -1922,9 +1922,9 @@ void LayerTreeHostImpl::CreateAndSetTileManager() {
 
   tile_manager_ =
       TileManager::Create(this,
+                          proxy_->ImplThreadTaskRunner(),
                           resource_pool_.get(),
                           raster_worker_pool_->AsRasterizer(),
-                          GetRendererCapabilities().allow_rasterize_on_demand,
                           rendering_stats_instrumentation_);
 
   UpdateTileManagerMemoryPolicy(ActualManagedMemoryPolicy());
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 494342e..45fefe5 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -232,7 +232,7 @@ class CC_EXPORT LayerTreeHostImpl
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE;
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE;
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE;
 
   // ScrollbarAnimationControllerClient implementation.
   virtual void PostDelayedScrollbarFade(const base::Closure& start_fade,