Revert of CQ to always post a message when Commit box is unchecked. (

Reason for revert:
This created a lot of spam at commit event for some obscure reason. I couldn't fix it fast, so reverting.

Original issue's description:
> Made _discard_pending() always post a message. Added meaningful
> default messages to all the places where it is called in the code.  In
> particular, CQ will now always post a message whenever the Commit
> checkbox is unchecked, for any reason.
> Updated unit tests accordingly, and made them a bit more robust by
> adding an error message to the failing FakeVerifier.
> This does NOT fix the bug, but will hopefully give more visibility to
> developers when a CL is dropped.
> BUG=238283
> Committed:

Review URL:

git-svn-id: svn:// 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed