Return overlay resources to renderers in larger batches.

cc/resources/resource_provider.h

Index: cc/resources/resource_provider.h
diff --git a/cc/resources/resource_provider.h b/cc/resources/resource_provider.h
index df3c5b85fb6bf1fa476f80761982df271ce19fa2..53096457c85d2b556e61e823e35378bb5c3f7e34 100644
--- a/cc/resources/resource_provider.h
+++ b/cc/resources/resource_provider.h
@@ -524,6 +524,11 @@ class CC_EXPORT ResourceProvider
 
   GLenum GetImageTextureTarget(gfx::BufferUsage usage, ResourceFormat format);
 
+  // Sets whether or not to store resources that are being returned to
+  // children to return them all at once. Setting this to false will return
+  // all accumulated resources.
+  void SetBatchReturnResources(bool aggregate);
+
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
@@ -774,6 +779,12 @@ class CC_EXPORT ResourceProvider
   std::unique_ptr<TextureIdAllocator> texture_id_allocator_;
   BufferToTextureTargetMap buffer_to_texture_target_map_;
 
+  // Keep track of whether deleted resources should be batched up or returned
+  // immediately.
+  bool batch_return_resources_ = false;
+  // Maps from a child id to the set of resources to be returned to it.
+  std::map<int, ResourceIdArray> batched_returning_resources_;

[Daniele Castagna, 2017/03/24 01:44:43]

How many child ids do you expect to have?
Should we use SmallMap instead?

+
   base::ThreadChecker thread_checker_;
 
   // A process-unique ID used for disambiguating memory dumps from different