Expire resources in ResourcePool after non-use

cc/resources/resource_pool.h

Index: cc/resources/resource_pool.h
diff --git a/cc/resources/resource_pool.h b/cc/resources/resource_pool.h
index 20a66f06a4f964ef049f9a9d7060e9ef2cb047ae..a83ada335780ce20667b838c41bf058c104dfb16 100644
--- a/cc/resources/resource_pool.h
+++ b/cc/resources/resource_pool.h
@@ -77,14 +77,26 @@ class CC_EXPORT ResourcePool : public base::trace_event::MemoryDumpProvider {
     uint64_t content_id() const { return content_id_; }
     void set_content_id(uint64_t content_id) { content_id_ = content_id; }
 
+    base::TimeTicks last_usage() const { return last_usage_; }
+    void set_last_usage(base::TimeTicks time) { last_usage_ = time; }
+
    private:
     explicit PoolResource(ResourceProvider* resource_provider)
         : ScopedResource(resource_provider), content_id_(0) {}
     uint64_t content_id_;
+    base::TimeTicks last_usage_;
   };
 
   void DidFinishUsingResource(scoped_ptr<PoolResource> resource);
   void DeleteResource(scoped_ptr<PoolResource> resource);
+  void DeleteUnusedResource(scoped_ptr<PoolResource> resource);
+
+  // Functions which manage periodic eviction of expired resources.
+  void ScheduleEvictExpiredResources();
+  void EvictExpiredResources();
+  void EvictResourcesNotUsedSince(base::TimeTicks time_limit);
+  bool HasEvictableResources() const;
+  base::TimeTicks GetUsageTimeForLRUResource() const;
 
   ResourceProvider* resource_provider_;
   const GLenum target_;
@@ -102,6 +114,12 @@ class CC_EXPORT ResourcePool : public base::trace_event::MemoryDumpProvider {
   using ResourceMap = base::ScopedPtrMap<ResourceId, scoped_ptr<PoolResource>>;
   ResourceMap in_use_resources_;
 
+  bool evict_expired_resources_pending_;
+  base::TimeDelta resource_expiration_delay_;
+  base::Closure evict_expired_resources_callback_;
+
+  base::WeakPtrFactory<ResourcePool> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ResourcePool);
 };