Allow browser to handle all WebUI navigations.

BUG=113496
TEST="Google Dashboard" link in Sync settings loads in new process.


Review URL: http://codereview.chromium.org/9663045

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126949 0039d316-1c4b-4281-b951-d872f2087c98
   virtual void SetUp() {
    old_client_ = content::GetContentClient();
    content::SetContentClient(&client_);
     old_browser_client_ = content::GetContentClient()->browser();
     content::GetContentClient()->set_browser(&browser_client_);
     url_util::AddStandardScheme(kPrivilegedScheme);
    url_util::AddStandardScheme(chrome::kChromeUIScheme);
  }

   virtual void SetUp() {
     old_browser_client_ = content::GetContentClient()->browser();
     content::GetContentClient()->set_browser(&browser_client_);
     url_util::AddStandardScheme(kPrivilegedScheme);
    url_util::AddStandardScheme(chrome::kChromeUIScheme);
  }
