cc @btownsend
cc @kashyapnitin : Can you find out if someone from the ads side needs to verify this?

@cramforce Can the ids be also added to adsense's iframe? The same global and same ids.

Verification:
I patched the commit on my machine and got following results:

GA hit: https://www.google-analytics.com/r/collect?[...]cid=amp-coHUf9oQWyYVp-rq-9U1QKWoGy92tAAN1H3B8kjUd7hl5pOysDwUwFzWBqSv9W_2&[...]&a=6361&[...]

Doubleclick hits: https://securepubads.g.doubleclick.net/gampad/ads?[...]loc=http%3A%2F%2Fads.localhost%3A8000%2Fdist.3p%2Fcurrent%2Fframe.max.html%23%7B%22slot%22%3A%22%2F4119129%2Fmobile_ad_banner%22%2C%22width%22%3A320%2C%22height%22%3A50%2C%22initialWindowWidth%22%3A320%2C%22initialWindowHeight%22%3A50%2C%22type%22%3A%22doubleclick%22%2C%22_context%22%3A%7B%22referrer%22%3A%22http%3A%2F%2Flocalhost%3A8000%2Fexamples.build%2F%22%2C%22canonicalUrl%22%3A%22http%3A%2F%2Fnonblocking.io%2F%22%2C%22pageViewId%22%3A%226361%22%2C%22clientId%22%3A%22amp-coHUf9oQWyYVp-rq-9U1QKWoGy92tAAN1H3B8kjUd7hl5pOysDwUwFzWBqSv9W_2%22%2C%22location%22%3A%7B%22href%22%3A%22http%3A%2F%2Flocalhost%3A8000%2Fexamples.build%2Fads.amp.max.html%22%7D%2C%22tagName%22%3A%22AMP-AD%22%2C%22mode%22%3A%7B%22localDev%22%3Atrue%2C%22minified%22%3Afalse%7D%7D%7D&[...]&ga_vid=amp-coHUf9oQWyYVp-rq-9U1QKWoGy92tAAN1H3B8kjUd7hl5pOysDwUwFzWBqSv9W_2&ga_sid=1454449683&ga_hid=6361

Done

lgtm