Update from https://crrev.com/305340

cc/layers/picture_layer_impl_unittest.cc

 // Copyright 2013 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/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <utility>
@@ skipping 1208 matching lines @@
 
   // Mask layers have a tiling with a single tile in it.
   EXPECT_EQ(1u, active_layer_->HighResTiling()->AllTilesForTesting().size());
   // The mask resource exists.
   ResourceProvider::ResourceId mask_resource_id;
   gfx::Size mask_texture_size;
   active_layer_->GetContentsResourceId(&mask_resource_id, &mask_texture_size);
   EXPECT_NE(0u, mask_resource_id);
   EXPECT_EQ(mask_texture_size, active_layer_->bounds());
 
+  // Drop resources and recreate them, still the same.
+  old_pending_layer_->ReleaseResources();
+  active_layer_->ReleaseResources();
+  SetupDrawPropertiesAndUpdateTiles(active_layer_, 1.f, 1.f, 1.f, 1.f, false);
+  active_layer_->HighResTiling()->CreateAllTilesForTesting();
+  EXPECT_EQ(1u, active_layer_->HighResTiling()->AllTilesForTesting().size());
+  EXPECT_NE(0u, mask_resource_id);
+  EXPECT_EQ(mask_texture_size, active_layer_->bounds());
+
   // Resize larger than the max texture size.
   int max_texture_size = host_impl_.GetRendererCapabilities().max_texture_size;
   scoped_refptr<FakePicturePileImpl> huge_pile =
       FakePicturePileImpl::CreateFilledPile(
           tile_size, gfx::Size(max_texture_size + 1, 10));
   SetupPendingTree(huge_pile);
   pending_layer_->set_is_mask(true);
 
   SetupDrawPropertiesAndUpdateTiles(pending_layer_, 1.f, 1.f, 1.f, 1.f, false);
   EXPECT_EQ(1.f, pending_layer_->HighResTiling()->contents_scale());
   EXPECT_EQ(1u, pending_layer_->num_tilings());
 
   pending_layer_->HighResTiling()->CreateAllTilesForTesting();
   host_impl_.tile_manager()->InitializeTilesWithResourcesForTesting(
       pending_layer_->HighResTiling()->AllTilesForTesting());
 
   ActivateTree();
 
   // Mask layers have a tiling, but there should be no tiles in it.
   EXPECT_EQ(0u, active_layer_->HighResTiling()->AllTilesForTesting().size());
   // The mask resource is empty.
   active_layer_->GetContentsResourceId(&mask_resource_id, &mask_texture_size);
   EXPECT_EQ(0u, mask_resource_id);
+
+  // Drop resources and recreate them, still the same.
+  old_pending_layer_->ReleaseResources();
+  active_layer_->ReleaseResources();
+  SetupDrawPropertiesAndUpdateTiles(active_layer_, 1.f, 1.f, 1.f, 1.f, false);
+  active_layer_->HighResTiling()->CreateAllTilesForTesting();
+  EXPECT_EQ(0u, active_layer_->HighResTiling()->AllTilesForTesting().size());
+  active_layer_->GetContentsResourceId(&mask_resource_id, &mask_texture_size);
+  EXPECT_EQ(0u, mask_resource_id);
 }
 
 TEST_F(PictureLayerImplTest, ScaledMaskLayer) {
   gfx::Size tile_size(100, 100);
 
   scoped_refptr<FakePicturePileImpl> valid_pile =
       FakePicturePileImpl::CreateFilledPile(tile_size, gfx::Size(1000, 1000));
   SetupPendingTree(valid_pile);
   pending_layer_->set_is_mask(true);
 
@@ skipping 3460 matching lines @@
   result = layer->CalculateTileSize(gfx::Size(447, 400));
   EXPECT_EQ(result.width(), 448);
   EXPECT_EQ(result.height(), 448);
   result = layer->CalculateTileSize(gfx::Size(500, 499));
   EXPECT_EQ(result.width(), 512);
   EXPECT_EQ(result.height(), 500 + 2);
 }
 
 }  // namespace
 }  // namespace cc