Cache.put() validation of Request properties

Cache.put() should fail the operation if request's scheme is not
"http" or "https", or if the method is not "GET"

Spec:
https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html

R=jkarlin@chromium.org
BUG=425505

Review URL: https://codereview.chromium.org/675733003

git-svn-id: svn://svn.chromium.org/blink/trunk@184310 bbb929c8-8fbe-4397-9dbb-9b2b20218538