cc: Add test for TiledLayerImpl mask with no resource

cc/layers/tiled_layer_impl_unittest.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/tiled_layer_impl.h"
 
 #include "cc/layers/append_quads_data.h"
 #include "cc/quads/tile_draw_quad.h"
 #include "cc/resources/layer_tiling_data.h"
 #include "cc/test/fake_impl_proxy.h"
@@ skipping 286 matching lines @@
       static_cast<size_t>(3 * 4 * tile_size.width() * tile_size.height()));
 
   ResourceProvider::ResourceId empty_resource(0);
   layer->PushTileProperties(0, 1, empty_resource, gfx::Rect(0, 0, 1, 1), false);
   layer->PushTileProperties(2, 3, empty_resource, gfx::Rect(0, 0, 1, 1), false);
   layer->PushTileProperties(2, 0, empty_resource, gfx::Rect(0, 0, 1, 1), false);
 
   EXPECT_EQ(layer->GPUMemoryUsageInBytes(), 0u);
 }
 
+TEST_F(TiledLayerImplTest, EmptyMask) {
+  gfx::Size tile_size(20, 20);
+  gfx::Size layer_size(0, 0);
+  scoped_ptr<TiledLayerImpl> layer =
+      CreateLayer(tile_size, layer_size, LayerTilingData::NO_BORDER_TEXELS);
+
+  EXPECT_EQ(0u, layer->ContentsResourceId());
+  EXPECT_EQ(0, layer->TilingForTesting()->num_tiles_x());
+  EXPECT_EQ(0, layer->TilingForTesting()->num_tiles_y());
+}
+
 }  // namespace
 }  // namespace cc