cc: Use CheckedNumeric for resource size calculations.

cc/tiles/tile_manager.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/tiles/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 956 matching lines @@
 }
 
 TileManager::MemoryUsage::MemoryUsage(int64 memory_bytes, int resource_count)
     : memory_bytes_(memory_bytes), resource_count_(resource_count) {
 }
 
 // static
 TileManager::MemoryUsage TileManager::MemoryUsage::FromConfig(
     const gfx::Size& size,
     ResourceFormat format) {
-  return MemoryUsage(Resource::MemorySizeBytes(size, format), 1);
+  // We can use UncheckedMemorySizeBytes here since this is used with a tile
+  // size which is determined by the compositor (it's at most max texture size).
+  return MemoryUsage(Resource::UncheckedMemorySizeBytes(size, format), 1);
 }
 
 // static
 TileManager::MemoryUsage TileManager::MemoryUsage::FromTile(const Tile* tile) {
   const TileDrawInfo& draw_info = tile->draw_info();
   if (draw_info.resource_) {
     return MemoryUsage::FromConfig(draw_info.resource_->size(),
                                    draw_info.resource_->format());
   }
   return MemoryUsage();
@@ skipping 19 matching lines @@
   result -= other;
   return result;
 }
 
 bool TileManager::MemoryUsage::Exceeds(const MemoryUsage& limit) const {
   return memory_bytes_ > limit.memory_bytes_ ||
          resource_count_ > limit.resource_count_;
 }
 
 }  // namespace cc