tree ea402a94b835e6b69896362685f0a095b30b93e4
parent eea84e7e07ecf6ebb70ea5a6b0cde67f5a5576af
author Dave Borowitz <dborowitz@google.com> 1450825192 -0500
committer Dave Borowitz <dborowitz@google.com> 1450825443 -0500

Use descriptive error messages for MergeValidationExceptions

These are no longer tied to CommitMergeStatus, so we can actually say
what we mean rather than picking a similar-sounding status enum out of
a hat.

Change-Id: I7d1429c885a99503fe8cdfa8fe8925e7125fcb35