Added debugging output to mcov to help debug buildbot errors.
Die with non-zero return code if it can't operate properly.

Review URL: http://codereview.chromium.org/2630002

git-svn-id: http://src.chromium.org/svn/trunk/src/third_party/lcov@48991 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
1 file changed