cc: Do not cleanup tiles with raster tasks.

cc/resources/tile_manager.h

Index: cc/resources/tile_manager.h
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index 686d0d06aae9d1513915100210c1de18bb91fd1c..849e4a414146598411f5261cfcc6b0103be053e0 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -142,7 +142,11 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   void SetRasterizerForTesting(Rasterizer* rasterizer);
 
-  void CleanUpReleasedTilesForTesting() { CleanUpReleasedTiles(); }
+  void FreeResourcesAndCleanUpReleasedTilesForTesting() {
+    prioritized_tiles_.Clear();
+    FreeResourcesForReleasedTiles();
+    CleanUpReleasedTiles();
+  }
 
  protected:
   TileManager(TileManagerClient* client,
@@ -155,6 +159,7 @@ class CC_EXPORT TileManager : public RasterizerClient,
   friend class Tile;
   void DidChangeTilePriority(Tile* tile);
 
+  void FreeResourcesForReleasedTiles();
   void CleanUpReleasedTiles();
 
   // Overriden from RefCountedManager<Tile>: