Follow-up from postmortem: https://docs.google.com/a/google.com/document/d/1aM0Kr_vYhu2yWb0BFQRjWrJQnKWXRoINlnSx6PcGPCM/edit?usp=sharing

 Issue 670837  was identified as a release blocker, but was not tagged with OS-Android.  This led to the Chrome for Android team shipping a version to stable with the bug present.  This caused us to halt the rollout and respin, which costs the release team time and users money (via bandwidth).  We should implement a process to explicitly review all release blocking bugs to cross-verify platform applicability so that this does not occur again.