browser: Move FindBrowserWithWebContents() into chrome namespace.

BUG=133088
TBR=ben@chromium.org


Review URL: https://chromiumcodereview.appspot.com/11434074

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@170686 0039d316-1c4b-4281-b951-d872f2087c98
59 files changed