android: Fix ContentUtilBrowserTest to switch to delegated rendering for android

BUG=326363
NOTRY=true

Review URL: https://codereview.chromium.org/148343006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249488 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249488
Add missing descriptions for SBClientDownload signature and zipfile related histograms.

BUG=none
R=asvitkine@chromium.org

Review URL: https://codereview.chromium.org/156153003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249489 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249489