[cc] Fix CompositorFrameSinkSupport BeginFrameAck interface.

content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc b/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
index 80d781f5a5713d475f31710e5353c79d25815c90..4dd8f907fcf6e807cab2c74e8c0ad065e2704196 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
@@ -140,6 +140,7 @@ cc::CompositorFrame CreateDelegatedFrame(float scale_factor,
                                          const gfx::Rect& damage) {
   cc::CompositorFrame frame;
   frame.metadata.device_scale_factor = scale_factor;
+  frame.metadata.begin_frame_ack = cc::BeginFrameAck(0, 1, 1, 0, true);
 
   std::unique_ptr<cc::RenderPass> pass = cc::RenderPass::Create();
   pass->SetNew(1, gfx::Rect(size), damage, gfx::Transform());