There are 2 layout files for doorhangerpopup (and site_identity_popup) differing only my the width attribute. A good approach would be specify it as a theme level attribute, and use it here.
Created attachment 724778 [details] [diff] [review] Patch Finally, just one layout file.
Created attachment 724787 [details] [diff] [review] Patch This is a better patch.
Backed out the whole push in https://hg.mozilla.org/integration/mozilla-inbound/rev/5eb7efc431c8 for mochitest-1 and robocop-2 errors about "Error inflating class android.widget.Button" like https://tbpl.mozilla.org/php/getParsedLog.php?id=20799813&tree=Mozilla-Inbound and https://tbpl.mozilla.org/php/getParsedLog.php?id=20798777&tree=Mozilla-Inbound