<webview>: Move Geolocation permission to chrome layer.

This CL also exposes the userGesture field to the geolocation permissionrequest event.

BUG=330264

Review URL: https://codereview.chromium.org/235633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263926 0039d316-1c4b-4281-b951-d872f2087c98
23 files changed