Added the Vulkan Context Provider implementation.

content/browser/compositor/browser_compositor_output_surface.h

Index: content/browser/compositor/browser_compositor_output_surface.h
diff --git a/content/browser/compositor/browser_compositor_output_surface.h b/content/browser/compositor/browser_compositor_output_surface.h
index 02f284c18339d80b6a812d6fa0806f774bd4d25c..a4ef5add3a7bf225442c96e3609750c4fdab743f 100644
--- a/content/browser/compositor/browser_compositor_output_surface.h
+++ b/content/browser/compositor/browser_compositor_output_surface.h
@@ -79,6 +79,13 @@ class CONTENT_EXPORT BrowserCompositorOutputSurface
       const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
       base::SingleThreadTaskRunner* task_runner);
 
+#if defined(ENABLE_VULKAN)
+  // Constructor used by the Vulkan implementation.
+  BrowserCompositorOutputSurface(
+      const scoped_refptr<cc::VulkanContextProvider>& vulkan_context_provider,
+      const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager);
+#endif
+
   scoped_refptr<ui::CompositorVSyncManager> vsync_manager_;
   std::unique_ptr<cc::SyntheticBeginFrameSource> synthetic_begin_frame_source_;
   ReflectorImpl* reflector_;