Disable BrowserEncodingTest.TestEncodingAutoDetect

BUG=351325
TBR=cpu,jochen
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/195373002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256556 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256556