GLRenderer should regularly call ResourcePool::CheckBusyResources.

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 46 matching lines @@
 
   // Called when a resource's content has been fully replaced (and is completely
   // valid). Updates the resource's content ID to its new value.
   void OnContentReplaced(ResourceId resource_id, uint64_t content_id);
   void ReleaseResource(Resource* resource);
 
   void SetResourceUsageLimits(size_t max_memory_usage_bytes,
                               size_t max_resource_count);
 
   void ReduceResourceUsage();
+
+  // Must be called regularly to move resources from the busy pool to the unused
+  // pool.
   void CheckBusyResources();
 
   size_t memory_usage_bytes() const { return in_use_memory_usage_bytes_; }
   size_t resource_count() const { return in_use_resources_.size(); }
 
   // Overridden from base::trace_event::MemoryDumpProvider:
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
   size_t GetTotalMemoryUsageForTesting() const {
@@ skipping 82 matching lines @@
   base::TimeDelta resource_expiration_delay_;
 
   base::WeakPtrFactory<ResourcePool> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_POOL_H_