Update from chromium https://crrev.com/302282

cc/resources/resource_pool.h

 // 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.
 
 #ifndef CC_RESOURCES_RESOURCE_POOL_H_
 #define CC_RESOURCES_RESOURCE_POOL_H_
 
 #include <list>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 16 matching lines @@
   virtual ~ResourcePool();
 
   scoped_ptr<ScopedResource> AcquireResource(const gfx::Size& size);
   void ReleaseResource(scoped_ptr<ScopedResource>);
 
   void SetResourceUsageLimits(size_t max_memory_usage_bytes,
                               size_t max_unused_memory_usage_bytes,
                               size_t max_resource_count);
 
   void ReduceResourceUsage();
-  void CheckBusyResources();
+  // This might block if |wait_if_needed| is true and one of the currently
+  // busy resources has a read lock fence that needs to be waited upon before
+  // it can be locked for write again.
+  void CheckBusyResources(bool wait_if_needed);
 
   size_t total_memory_usage_bytes() const { return memory_usage_bytes_; }
   size_t acquired_memory_usage_bytes() const {
     return memory_usage_bytes_ - unused_memory_usage_bytes_;
   }
   size_t total_resource_count() const { return resource_count_; }
   size_t acquired_resource_count() const {
     return resource_count_ - unused_resources_.size();
   }
+  size_t busy_resource_count() const { return busy_resources_.size(); }
 
   ResourceFormat resource_format() const { return format_; }
 
  protected:
   ResourcePool(ResourceProvider* resource_provider,
                GLenum target,
                ResourceFormat format);
 
   bool ResourceUsageTooHigh();
 
@@ skipping 13 matching lines @@
   typedef std::list<ScopedResource*> ResourceList;
   ResourceList unused_resources_;
   ResourceList busy_resources_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_POOL_H_