Fix freeing of PNaCl translation cache backend

Don't free the backend if it is in the process of being initialized.

BUG=339498

Review URL: https://codereview.chromium.org/133503006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248246 0039d316-1c4b-4281-b951-d872f2087c98
[Android WebView] Tiny clean-up of license checking

1. Try removing third_party/accessibility-developer-tools from KNOWN_ISSUES

2. Brush up output from 'incompatible_directories' command

Review URL: https://codereview.chromium.org/131163006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248247 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248247