Update from https://crrev.com/309415

cc/test/fake_picture_layer_tiling_client.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/test/fake_picture_layer_tiling_client.h"
 
 #include <limits>
 
 #include "cc/test/fake_picture_pile_impl.h"
 #include "cc/test/fake_tile_manager.h"
 
 namespace cc {
 
 FakePictureLayerTilingClient::FakePictureLayerTilingClient()
     : tile_manager_(new FakeTileManager(&tile_manager_client_)),
       pile_(FakePicturePileImpl::CreateInfiniteFilledPile()),
-      twin_tiling_(NULL),
-      recycled_twin_tiling_(NULL),
-      allow_create_tile_(true),
+      twin_set_(nullptr),
+      twin_tiling_(nullptr),
+      recycled_twin_tiling_(nullptr),
       max_tile_priority_bin_(TilePriority::NOW) {
 }
 
 FakePictureLayerTilingClient::FakePictureLayerTilingClient(
     ResourceProvider* resource_provider)
     : resource_pool_(
           ResourcePool::Create(resource_provider, GL_TEXTURE_2D, RGBA_8888)),
       tile_manager_(
           new FakeTileManager(&tile_manager_client_, resource_pool_.get())),
       pile_(FakePicturePileImpl::CreateInfiniteFilledPile()),
-      twin_tiling_(NULL),
-      recycled_twin_tiling_(NULL),
-      allow_create_tile_(true),
+      twin_set_(nullptr),
+      twin_tiling_(nullptr),
+      recycled_twin_tiling_(nullptr),
       max_tile_priority_bin_(TilePriority::NOW) {
 }
 
 FakePictureLayerTilingClient::~FakePictureLayerTilingClient() {
 }
 
 scoped_refptr<Tile> FakePictureLayerTilingClient::CreateTile(
-    PictureLayerTiling*,
+    float content_scale,
     const gfx::Rect& rect) {
-  if (!allow_create_tile_)
-    return scoped_refptr<Tile>();
   return tile_manager_->CreateTile(pile_.get(), tile_size_, rect, 1, 0, 0, 0);
 }
 
 void FakePictureLayerTilingClient::SetTileSize(const gfx::Size& tile_size) {
   tile_size_ = tile_size;
 }
 
 gfx::Size FakePictureLayerTilingClient::CalculateTileSize(
     const gfx::Size& /* content_bounds */) const {
   return tile_size_;
 }
 
 TilePriority::PriorityBin FakePictureLayerTilingClient::GetMaxTilePriorityBin()
     const {
   return max_tile_priority_bin_;
 }
 
 const Region* FakePictureLayerTilingClient::GetPendingInvalidation() {
   return &invalidation_;
 }
 
 const PictureLayerTiling*
 FakePictureLayerTilingClient::GetPendingOrActiveTwinTiling(
     const PictureLayerTiling* tiling) const {
-  return twin_tiling_;
+  if (!twin_set_)
+    return twin_tiling_;
+  for (size_t i = 0; i < twin_set_->num_tilings(); ++i) {
+    if (twin_set_->tiling_at(i)->contents_scale() == tiling->contents_scale())
+      return twin_set_->tiling_at(i);
+  }
+  return nullptr;
 }
 
 PictureLayerTiling* FakePictureLayerTilingClient::GetRecycledTwinTiling(
     const PictureLayerTiling* tiling) {
   return recycled_twin_tiling_;
 }
 
 WhichTree FakePictureLayerTilingClient::GetTree() const {
   return tree_;
 }
 
 bool FakePictureLayerTilingClient::RequiresHighResToDraw() const {
   return false;
 }
 
 }  // namespace cc