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

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 82b6bf4913ea3a47b0ff04661c1870a4eace4535..51e3c8eedb41aa23e9943d3d13d15d91f8b72d7a 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -365,27 +365,28 @@ scoped_ptr<base::Value> RasterTaskCompletionStatsAsValue(
 // static
 scoped_ptr<TileManager> TileManager::Create(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
     Rasterizer* gpu_rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation) {
   return make_scoped_ptr(new TileManager(client,
+                                         task_runner,
                                          resource_pool,
                                          rasterizer,
                                          gpu_rasterizer,
-                                         use_rasterize_on_demand,
                                          rendering_stats_instrumentation));
 }
 
 TileManager::TileManager(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
     Rasterizer* gpu_rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
     : client_(client),
+      task_runner_(task_runner),
       resource_pool_(resource_pool),
       prioritized_tiles_dirty_(false),
       all_tiles_that_need_to_be_rasterized_have_memory_(true),
@@ -398,7 +399,8 @@ 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* rasterizers[NUM_RASTERIZER_TYPES] = {
       rasterizer,      // RASTERIZER_TYPE_DEFAULT
       gpu_rasterizer,  // RASTERIZER_TYPE_GPU
@@ -535,12 +537,14 @@ 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() {
@@ -552,7 +556,7 @@ void TileManager::DidFinishRunningTasksRequiredForActivation() {
   if (!all_tiles_required_for_activation_have_memory_)
     return;
 
-  client_->NotifyReadyToActivate();
+  ScheduleCheckIfReadyToActivate();
 }
 
 void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
@@ -671,7 +675,7 @@ 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;
     }
 
@@ -860,7 +864,7 @@ void TileManager::AssignGpuMemoryToTiles(
 
     // If the tile is not needed, free it up.
     if (mts.bin == NEVER_BIN) {
-      FreeResourcesForTile(tile);
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
       continue;
     }
 
@@ -902,14 +906,19 @@ 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;
@@ -1004,6 +1013,14 @@ 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",
@@ -1200,11 +1217,11 @@ 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,
@@ -1640,4 +1657,38 @@ void TileManager::SetRasterizersForTesting(Rasterizer* rasterizer,
       RasterizerDelegate::Create(this, rasterizers, arraysize(rasterizers));
 }
 
+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_delegate_->CheckForCompletedTasks();
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
+
+  if (IsReadyToActivate())
+    client_->NotifyReadyToActivate();
+}
+
 }  // namespace cc