Inform apps whether they are running in a Chrome OS kiosk session
This CL extends the definition of the launchData argument that Chrome
passes to apps with the chrome.app.runtime.onLaunched event callback.
The newly added isKioskSession field will be |true| when an app is
launched in a Chrome OS kiosk session.
BUG=252934
TEST=Manual, updated browser tests
Review URL: https://chromiumcodereview.appspot.com/
23625011
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222804 0039d316-1c4b-4281-b951-d872f2087c98