Added an extra sync token field for extra command buffer identification.

gpu/command_buffer/tests/gl_manager.h

Index: gpu/command_buffer/tests/gl_manager.h
diff --git a/gpu/command_buffer/tests/gl_manager.h b/gpu/command_buffer/tests/gl_manager.h
index 6031bf697492a8ee7c682ec65009308a5517001e..72a39719c9d381d8b70985a41bd53ad9bb411c06 100644
--- a/gpu/command_buffer/tests/gl_manager.h
+++ b/gpu/command_buffer/tests/gl_manager.h
@@ -133,6 +133,7 @@ class GLManager : private GpuControl {
   bool IsGpuChannelLost() override;
   gpu::CommandBufferNamespace GetNamespaceID() const override;
   uint64_t GetCommandBufferID() const override;
+  uint32_t GetExtraCommandBufferData() const override;
   uint64_t GenerateFenceSyncRelease() override;
   bool IsFenceSyncRelease(uint64_t release) override;
   bool IsFenceSyncFlushed(uint64_t release) override;