Move another batch of functions for WebContents to TabContents. This also

      updates the Dev tools manager to take a TabContents (a pointer was being
passed from the TabContents which made it break).
Review URL: http://codereview.chromium.org/92101

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@14412 0039d316-1c4b-4281-b951-d872f2087c98