Update from https://crrev.com/314320

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 da888cd77297c66a19ba39bc84425ce3abe040f4..2b247aa20856e22a2ba12b321ce0d3dd6f2e9d7c 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -362,6 +362,11 @@ void TileManager::PrepareTiles(
     scoped_ptr<RasterTilePriorityQueue> raster_priority_queue(
         client_->BuildRasterQueue(global_state_.tree_priority,
                                   RasterTilePriorityQueue::Type::ALL));
+    // Inform the client that will likely require a draw if the top tile is
+    // required for draw.
+    client_->SetIsLikelyToRequireADraw(
+        !raster_priority_queue->IsEmpty() &&
+        raster_priority_queue->Top()->required_for_draw());
     AssignGpuMemoryToTiles(raster_priority_queue.get(),
                            scheduled_raster_task_limit_,
                            &tiles_that_need_to_be_rasterized);
@@ -830,8 +835,10 @@ void TileManager::UpdateTileDrawInfo(
 
   if (analysis.is_solid_color) {
     draw_info.set_solid_color(analysis.solid_color);
-    resource_pool_->ReleaseResource(resource.Pass());
+    if (resource)
+      resource_pool_->ReleaseResource(resource.Pass());
   } else {
+    DCHECK(resource);
     draw_info.set_use_resource();
     draw_info.resource_ = resource.Pass();
   }
@@ -863,31 +870,31 @@ void TileManager::SetTileTaskRunnerForTesting(
   tile_task_runner_->SetClient(this);
 }
 
-bool TileManager::IsReadyToActivate() const {
-  TRACE_EVENT0("cc", "TileManager::IsReadyToActivate");
-  const std::vector<PictureLayerImpl*>& layers = client_->GetPictureLayers();
-
-  // TODO(vmpstr): Replace this with building a REQUIRED_TO_ACTIVATE raster
-  // queue and checking if the tiles it contains are all ready to draw.
-  for (const auto& layer : layers) {
-    if (!layer->AllTilesRequiredForActivationAreReadyToDraw())
+bool TileManager::AreRequiredTilesReadyToDraw(
+    RasterTilePriorityQueue::Type type) const {
+  scoped_ptr<RasterTilePriorityQueue> raster_priority_queue(
+      client_->BuildRasterQueue(global_state_.tree_priority, type));
+  // It is insufficient to check whether the raster queue we constructed is
+  // empty. The reason for this is that there are situations (rasterize on
+  // demand) when the tile both needs raster and it's ready to draw. Hence, we
+  // have to iterate the queue to check whether the required tiles are ready to
+  // draw.
+  for (; !raster_priority_queue->IsEmpty(); raster_priority_queue->Pop()) {
+    if (!raster_priority_queue->Top()->IsReadyToDraw())
       return false;
   }
-
   return true;
 }
+bool TileManager::IsReadyToActivate() const {
+  TRACE_EVENT0("cc", "TileManager::IsReadyToActivate");
+  return AreRequiredTilesReadyToDraw(
+      RasterTilePriorityQueue::Type::REQUIRED_FOR_ACTIVATION);
+}
 
 bool TileManager::IsReadyToDraw() const {
-  const std::vector<PictureLayerImpl*>& layers = client_->GetPictureLayers();
-
-  // TODO(vmpstr): Replace this with building a REQUIRED_TO_DRAW raster queue
-  // and checking if the tiles it contains are all ready to draw.
-  for (const auto& layer : layers) {
-    if (!layer->AllTilesRequiredForDrawAreReadyToDraw())
-      return false;
-  }
-
-  return true;
+  TRACE_EVENT0("cc", "TileManager::IsReadyToDraw");
+  return AreRequiredTilesReadyToDraw(
+      RasterTilePriorityQueue::Type::REQUIRED_FOR_DRAW);
 }
 
 void TileManager::NotifyReadyToActivate() {