Add simple PRESUBMIT check to ensure that all files ending with .json can
be loaded as json.

R=jochen@chromium.org, maruel@chromium.org
BUG=366395

Review URL: https://codereview.chromium.org/258473002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265881 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed