cc: Add ScopedReadLockGpuMemoryBuffer

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>
 
@@ skipping 147 matching lines @@
   // the resource).
   void CopyToResource(ResourceId id,
                       const uint8_t* image,
                       const gfx::Size& image_size);
 
   // Generates sync tokesn for resources which need a sync token.
   void GenerateSyncTokenForResource(ResourceId resource_id);
   void GenerateSyncTokenForResources(const ResourceIdArray& resource_ids);
 
   // Creates accounting for a child. Returns a child ID.
-  int CreateChild(const ReturnCallback& return_callback);
+  int CreateChild(const ReturnCallback& return_callback,
+                  int gpu_memory_buffer_client_id);
 
   // Destroys accounting for the child, deleting all accounted resources.
   void DestroyChild(int child);
 
   // Sets whether resources need sync points set on them when returned to this
   // child. Defaults to true.
   void SetChildNeedsSyncTokens(int child, bool needs_sync_tokens);
 
   // Gets the child->parent resource ID map.
   const ResourceIdMap& GetChildToParentMap(int child) const;
@@ skipping 146 matching lines @@
 
    private:
     ResourceProvider* resource_provider_;
     ResourceProvider::Resource* resource_;
     std::unique_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer_;
     base::ThreadChecker thread_checker_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedWriteLockGpuMemoryBuffer);
   };
 
+  class CC_EXPORT ScopedReadLockGpuMemoryBuffer {
+   public:
+    ScopedReadLockGpuMemoryBuffer(ResourceProvider* resource_provider,
+                                  ResourceId resource_id);
+    ~ScopedReadLockGpuMemoryBuffer();
+
+    // This may return nullptr.
+    gfx::GpuMemoryBuffer* GetGpuMemoryBuffer() const;
+
+    // This returns the GL texture that is backed by a GL image bound to the
+    // resource's GpuMemoryBuffer.
+    unsigned GetTextureId() const;
+
+   private:
+    ResourceProvider* resource_provider_;
+    ResourceId resource_id_;
+    const ResourceProvider::Resource* resource_;
+    base::ThreadChecker thread_checker_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedReadLockGpuMemoryBuffer);
+  };
+
   class CC_EXPORT ScopedWriteLockGr {
    public:
     ScopedWriteLockGr(ResourceProvider* resource_provider,
                       ResourceId resource_id);
     ~ScopedWriteLockGr();
 
     void InitSkSurface(bool use_distance_field_text,
                        bool can_use_lcd_text,
                        int msaa_sample_count);
     void ReleaseSkSurface();
@@ skipping 237 matching lines @@
   using ResourceMap = std::unordered_map<ResourceId, Resource>;
 
   struct Child {
     Child();
     Child(const Child& other);
     ~Child();
 
     ResourceIdMap child_to_parent_map;
     ResourceIdMap parent_to_child_map;
     ReturnCallback return_callback;
+    int gpu_memory_buffer_client_id;
     bool marked_for_deletion;
     bool needs_sync_tokens;
   };
   using ChildMap = std::unordered_map<int, Child>;
 
   bool ReadLockFenceHasPassed(const Resource* resource) {
     return !resource->read_lock_fence.get() ||
            resource->read_lock_fence->HasPassed();
   }
 
   ResourceId CreateGLTexture(const gfx::Size& size,
                              TextureHint hint,
                              ResourceType type,
                              ResourceFormat format);
   ResourceId CreateBitmap(const gfx::Size& size);
   Resource* InsertResource(ResourceId id, Resource resource);
   Resource* GetResource(ResourceId id);
-  const Resource* LockForRead(ResourceId id);
+  const Resource* LockForRead(ResourceId id, bool create_gpu_memory_buffer);
   void UnlockForRead(ResourceId id);
   Resource* LockForWrite(ResourceId id);
   void UnlockForWrite(Resource* resource);
 
   static void PopulateSkBitmapWithResource(SkBitmap* sk_bitmap,
                                            const Resource* resource);
 
   void CreateMailboxAndBindResource(gpu::gles2::GLES2Interface* gl,
                                     Resource* resource);
 
@@ skipping 61 matching lines @@
   // A process-unique ID used for disambiguating memory dumps from different
   // resource providers.
   int tracing_id_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_RESOURCE_PROVIDER_H_