UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3195.0 Safari/537.36

Steps to reproduce the problem:
1. run content_browsertests.ScreenOrientationOOPIFBrowserTest test with --gtest_repeat=10 --gtest_break_on_failure

What is the expected behavior?
Every run passes

What went wrong?
Sometimes test fails

Did this work before? N/A 

Chrome version: 62.0.3195.0  Channel: dev
OS Version: Ubuntu 14.04
Flash Version: 

I found that there is a race condition between the post of DidReceiveCompositorFrameAck and call of SendFakeScreenOrientation. The first call checks widget size is not empty and the second sets it to zero. And there is no code to wait task posting.