Remove squashing from about:flags

To deter people from enabling it which is polluting crash reports

BUG=330269

Review URL: https://codereview.chromium.org/115503005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242257 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242257