Return overlay resources to renderers in larger batches.

cc/resources/resource_provider.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_PROVIDER_H_
 #define CC_RESOURCES_RESOURCE_PROVIDER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <deque>
 #include <memory>
 #include <set>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>
 #include <vector>
 
 #include "base/callback.h"
+#include "base/containers/small_map.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "cc/base/resource_id.h"
 #include "cc/cc_export.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/renderer_settings.h"
@@ skipping 406 matching lines @@
     ResourceFormat format_;
     gfx::BufferUsage usage_;
     gfx::Size size_;
     std::unique_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer_;
     gfx::ColorSpace color_space_;
     base::ThreadChecker thread_checker_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedWriteLockGpuMemoryBuffer);
   };
 
+  // All resources that are returned to children while an instance of this
+  // class exists will be stored and returned when the instance is destroyed.
+  class CC_EXPORT ScopedBatchReturnResources {
+   public:
+    explicit ScopedBatchReturnResources(ResourceProvider* resource_provider);
+    ~ScopedBatchReturnResources();
+
+   private:
+    ResourceProvider* resource_provider_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedBatchReturnResources);
+  };
+
   class Fence : public base::RefCounted<Fence> {
    public:
     Fence() {}
 
     virtual void Set() = 0;
     virtual bool HasPassed() = 0;
     virtual void Wait() = 0;
 
    protected:
     friend class base::RefCounted<Fence>;
@@ skipping 60 matching lines @@
 #endif
 
   void WaitSyncTokenIfNeeded(ResourceId id);
 
   static GLint GetActiveTextureUnit(gpu::gles2::GLES2Interface* gl);
 
   void ValidateResource(ResourceId id) const;
 
   GLenum GetImageTextureTarget(gfx::BufferUsage usage, ResourceFormat format);
 
+  void SetBatchReturnResources(bool aggregate);

[Daniele Castagna, 2017/03/27 13:38:11]

nit: Can this be moved away from the public ResourceProvider API?
Maybe it could be private and friend of the ScopedBatchReturnResources, WDYT?

+
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
   int tracing_id() const { return tracing_id_; }
 
  private:
   struct Resource {
     enum Origin { INTERNAL, EXTERNAL, DELEGATED };
     enum SynchronizationState {
@@ skipping 230 matching lines @@
   BlockingTaskRunner* blocking_main_thread_task_runner_;
   bool lost_context_provider_;
   ResourceId next_id_;
   ResourceMap resources_;
   int next_child_;
   ChildMap children_;
   scoped_refptr<Fence> current_read_lock_fence_;
   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.
+  base::SmallMap<std::map<int, ResourceIdArray>> batched_returning_resources_;
+
   base::ThreadChecker thread_checker_;
 
   // A process-unique ID used for disambiguating memory dumps from different
   // resource providers.
   int tracing_id_;
 
 #if defined(OS_ANDROID)
   // Set of resource Ids that would like to be notified about promotion hints.
   ResourceIdSet wants_promotion_hints_set_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_