More -Wunused-private-field cleanups.

As of http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20120716/061102.html
the warning finds more bugs. Fix them.

BUG=none
TEST=none
TBR=owners

Review URL: https://chromiumcodereview.appspot.com/10800052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@147666 0039d316-1c4b-4281-b951-d872f2087c98
12 files changed