DevTools: Simplify isArrayLike() in injected script and extend InjectedScriptHost.type()

R=yurys@chromium.org, yurys

Review URL: https://codereview.chromium.org/464793002

git-svn-id: svn://svn.chromium.org/blink/trunk@180168 bbb929c8-8fbe-4397-9dbb-9b2b20218538