[zoom bubble] More prospective crash fixes via more null guarding.

[email protected],[email protected]
BUG=144879


Review URL: https://chromiumcodereview.appspot.com/11416125

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@169190 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed