Fix bugs detected by js compiler in remoting webapp.

BUG=309844
R=jamiewalch@chromium.org

Review URL: https://codereview.chromium.org/131483011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248572 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248572