cc: Remove resource freed tiles from tile manager pending gpu work set.

cc/tiles/tile_manager.cc

Index: cc/tiles/tile_manager.cc
diff --git a/cc/tiles/tile_manager.cc b/cc/tiles/tile_manager.cc
index 12f3dfd26e4880ac3ffa6c9244ccec2c8a89787f..d445417d7d6f8c2cdfe72639c2628356d43d8cc9 100644
--- a/cc/tiles/tile_manager.cc
+++ b/cc/tiles/tile_manager.cc
@@ -425,7 +425,6 @@ void TileManager::SetResources(ResourcePool* resource_pool,
 void TileManager::Release(Tile* tile) {
   FreeResourcesForTile(tile);
   tiles_.erase(tile->id());
-  pending_gpu_work_tiles_.erase(tile);
 }
 
 void TileManager::DidFinishRunningTileTasksRequiredForActivation() {
@@ -804,6 +803,7 @@ void TileManager::FreeResourcesForTile(Tile* tile) {
   Resource* resource = draw_info.TakeResource();
   if (resource)
     resource_pool_->ReleaseResource(resource);
+  pending_gpu_work_tiles_.erase(tile);

[vmpstr, 2017/02/09 18:49:20]

nit: might as well make it a part of the if

[sunnyps, 2017/02/10 23:49:59]

Done. Also added a DCHECK in CheckPendingGpuWorkTiles.

 }
 
 void TileManager::FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(