GitLab

We already have a way to send message via ExecuteJavaScript,
no need for another mechanism.

BUG=398046
TBR=jam

Review URL: https://codereview.chromium.org/418243003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288027 0039d316-1c4b-4281-b951-d872f2087c98