cc: Don't cleanup the pending twin's low res tiling.

cc/resources/picture_layer_tiling_set.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/resources/picture_layer_tiling_set.h"
 
 #include <limits>
 
 namespace cc {
 
@@ skipping 91 matching lines @@
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->RemoveTilesInRegion(region);
 }
 
 void PictureLayerTilingSet::SetCanUseLCDText(bool can_use_lcd_text) {
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->SetCanUseLCDText(can_use_lcd_text);
 }
 
 PictureLayerTiling* PictureLayerTilingSet::AddTiling(float contents_scale) {
-  for (size_t i = 0; i < tilings_.size(); ++i) {
-    // TODO(enne): temporary sanity CHECK for http://crbug.com/358350.
-    // If a duplicate tiling gets added, then many assumptions in
-    // PictureLayerImpl fail.
-    CHECK_NE(tilings_[i]->contents_scale(), contents_scale);
-  }
+  for (size_t i = 0; i < tilings_.size(); ++i)
+    DCHECK_NE(tilings_[i]->contents_scale(), contents_scale);
 
   tilings_.push_back(PictureLayerTiling::Create(contents_scale,
                                                 layer_bounds_,
                                                 client_));
   PictureLayerTiling* appended = tilings_.back();
 
   tilings_.sort(LargestToSmallestScaleFunctor());
   return appended;
 }
 
@@ skipping 222 matching lines @@
 }
 
 size_t PictureLayerTilingSet::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (size_t i = 0; i < tilings_.size(); ++i)
     amount += tilings_[i]->GPUMemoryUsageInBytes();
   return amount;
 }
 
 }  // namespace cc