cc: [WIP] Use worker context and OrderingBarrierCHROMIUM for one-copy.

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 2130bb7b1a983b19cfc9342aedcc5b75a66617f7..ccef1cd50389b7e7e7a0f40ebb3c2b8d883b379b 100644
--- a/cc/resources/resource_provider.h
+++ b/cc/resources/resource_provider.h
@@ -399,6 +399,29 @@ class CC_EXPORT ResourceProvider {
     DISALLOW_COPY_AND_ASSIGN(SynchronousFence);
   };
 
+  // Query object based fence implementation used to detect completion of copy
+  // texture operations. Fence has passed when query result is available.
+  class CopyTextureFence : public ResourceProvider::Fence {
+   public:
+    CopyTextureFence(gpu::gles2::GLES2Interface* gl, unsigned query_id)
+        : gl_(gl), query_id_(query_id) {}
+
+    // Overridden from ResourceProvider::Fence:
+    void Set() override {}
+    bool HasPassed() override;
+    void Wait() override;
+
+   private:
+    ~CopyTextureFence() override {}
+
+    void ProcessResult();
+
+    gpu::gles2::GLES2Interface* gl_;
+    unsigned query_id_;
+
+    DISALLOW_COPY_AND_ASSIGN(CopyTextureFence);
+  };
+
   // Acquire pixel buffer for resource. The pixel buffer can be used to
   // set resource pixels without performing unnecessary copying.
   void AcquirePixelBuffer(ResourceId resource);