Fix WeakPtrFactory member placement.

WeakPtrFactory should always be declared last, see class comments on it.

BUG=303818

Review URL: https://codereview.chromium.org/26329003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227584 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed