[cc] Fix CompositorFrameSinkSupport BeginFrameAck interface.

android_webview/browser/test/rendering_test.cc

Index: android_webview/browser/test/rendering_test.cc
diff --git a/android_webview/browser/test/rendering_test.cc b/android_webview/browser/test/rendering_test.cc
index c507324871c8e03cddfc735a1d5dd18ca7664266..0e0ab20027d5b5df16947582655ca9f1ea1e4b79 100644
--- a/android_webview/browser/test/rendering_test.cc
+++ b/android_webview/browser/test/rendering_test.cc
@@ -118,6 +118,8 @@ content::SynchronousCompositor* RenderingTest::ActiveCompositor() const {
 std::unique_ptr<cc::CompositorFrame> RenderingTest::ConstructEmptyFrame() {
   std::unique_ptr<cc::CompositorFrame> compositor_frame(
       new cc::CompositorFrame);
+  compositor_frame->metadata.begin_frame_ack =
+      cc::BeginFrameAck(0, 1, 1, 0, true);
   std::unique_ptr<cc::RenderPass> root_pass(cc::RenderPass::Create());
   gfx::Rect viewport(browser_view_renderer_->size());
   root_pass->SetNew(1, viewport, viewport, gfx::Transform());