[DevTools] Remove overlayContents parameter.

Frontend don't use this anymore.

BUG=318751

Review URL: https://codereview.chromium.org/136503004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244554 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244554
Disable the Run option in the context menu for blocked plugins if they were blocked by policy.

BUG=321772

Review URL: https://codereview.chromium.org/134233002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244555 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244555