Implemented new fence syncs which replaces the old sync points.

mojo/gles2/command_buffer_client_impl.h

Index: mojo/gles2/command_buffer_client_impl.h
diff --git a/mojo/gles2/command_buffer_client_impl.h b/mojo/gles2/command_buffer_client_impl.h
index b5e2db3227f30d334eaec95244ac95fd81a47856..2c3c92502112b88c174fa9b9dae3ef9628cd3349 100644
--- a/mojo/gles2/command_buffer_client_impl.h
+++ b/mojo/gles2/command_buffer_client_impl.h
@@ -76,6 +76,9 @@ class CommandBufferClientImpl : public mojo::CommandBufferLostContextObserver,
   bool IsGpuChannelLost() override;
   gpu::CommandBufferNamespace GetNamespaceID() const override;
   uint64_t GetCommandBufferID() const override;
+  uint64_t GenerateFenceSyncRelease() override;
+  bool IsFenceSyncRelease(uint64_t release) override;
+  bool IsFenceSyncFlushed(uint64_t release) override;
 
  private:
   class SyncClientImpl;
@@ -106,6 +109,9 @@ class CommandBufferClientImpl : public mojo::CommandBufferLostContextObserver,
   // Image IDs are allocated in sequence.
   int next_image_id_;
 
+  uint64_t next_fence_sync_release_;
+  uint64_t flushed_fence_sync_release_;
+
   const MojoAsyncWaiter* async_waiter_;
 };