Reject frames with invalid BeginFrameAck in CompositorFrameSinkSupport

cc/test/compositor_frame_helpers.h

Index: cc/test/compositor_frame_helpers.h
diff --git a/cc/test/compositor_frame_helpers.h b/cc/test/compositor_frame_helpers.h
new file mode 100644
index 0000000000000000000000000000000000000000..1c23b69463025c778e310731aa86d0652b400af1
--- /dev/null
+++ b/cc/test/compositor_frame_helpers.h
@@ -0,0 +1,19 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CC_TEST_COMPOSITOR_FRAME_HELPERS_H_
+#define CC_TEST_COMPOSITOR_FRAME_HELPERS_H_
+
+namespace cc {
+
+class CompositorFrame;
+
+namespace test {

[danakj, 2017/04/25 15:24:36]

Didn't realize we had other cc::test::FreeFunctions like this but we do,
interesting.

+
+CompositorFrame MakeCompositorFrame();
+
+}  // namespace test
+}  // namespace cc
+
+#endif  // CC_TEST_COMPOSITOR_FRAME_HELPERS_H_