OnSwapBuffersComplete in GpuSurfacelessBrowserCompositorOutputSurface is never called.

In OnSwapBuffersComplete we call PageFlipComplete in BufferQueue, which ensures
the buffers are recycled properly.
However, GpuSurfacelessBrowserCompositorOutputSurface::OnSwapBuffersComplete is
never called as GpuBrowserCompositorOutputSurface directly calls the base class
implementation. This CL fixes it.

BUG=380861

Review URL: https://codereview.chromium.org/697823002

Cr-Commit-Position: refs/heads/master@{#302479}

content/browser/compositor/gpu_browser_compositor_output_surface.cc

@@ -94,7 +94,7 @@ void GpuBrowserCompositorOutputSurface::OnSwapBuffersCompleted(
         FROM_HERE,
         base::Bind(&RenderWidgetHostImpl::CompositorFrameDrawn, latency_info));
   }
-  cc::OutputSurface::OnSwapBuffersComplete();
+  OnSwapBuffersComplete();
 #endif
 }