Revert "MediaStream API: Updating NavigatorUserMediaError"

This reverts commit d1bed3cedfe563f3e42d7ff646948a0988d1006d.

It looks like this CL broke a number of MediaStream infobar browser tests:

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&testType=browser_tests&tests=MediaStreamInfoBarTest.TestDenyingThenClearingStickyException,MediaStreamInfoBarTest.TestDismissingInfobar,MediaStreamInfoBarTest.DenyingCameraDoesNotCauseStickyDenyForMics,ActivityLogPrerenderTest.TestScriptInjected,MediaStreamInfoBarTest.DenyingMicStillSucceedsWithCameraForAudioVideoCalls,MediaStreamInfoBarTest.TestDenyingUserMedia,MediaStreamInfoBarTest.TestAcceptThenDenyWhichShouldBeSticky,MediaStreamInfoBarTest.DenyingMicDoesNotCauseStickyDenyForCameras,MediaStreamInfoBarTest.TestDismissIsNotSticky

See, for example,
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests%20(dbg)/builds/23/steps/browser_tests/logs/TestDenyingUserMedia

TBR=tommyw

Review URL: https://codereview.chromium.org/23534059

git-svn-id: svn://svn.chromium.org/blink/trunk@157752 bbb929c8-8fbe-4397-9dbb-9b2b20218538