Bug 1533679 is going to help running very basic puppeteer support but that won't help running much useful script as most will want to open a tab with a custom document.

This bug is about support Browser.newTab which allows opening such custom document. This methods depends on many CDP methods:

• Target.setDiscoverTargets
• Target.createTarget
• Target.attachToTarget
  And events:
• Target.targetCreated event
• Target.attachedToTarget event

As we don't have any way to run a puppeteer script from mozilla-central, you would have to run a script manually to assert this goal:

• First, run a server:

$ ./mach run --remote-debugging-port=9000 --headless

• Run nodejs script:

$ DEBUG="puppeteer:protocol" node script.js 

const puppeteer = require('puppeteer');

puppeteer.connect({ browserURL: "http://localhost:9000"}).then(browser => {
  const page = await browser.newPage();
  console.log("page", !!page);
  console.log("SUCCESS");
});

In order to be able to query/instantiate sub targets like remote frames, or tab targets from the MainProcessTarget,
we have to support session at the protocol layer.
This is all based on a sessionId attribute put on all inbound/outbound messages.

This patch will be later used, once we start instantiating sub targets.

Depends on D22694

Puppetteer enable all these domains. Implement enable methods in order to prevent it from crashing on that.

Depends on D22695

https://hg.mozilla.org/mozilla-central/rev/fde0fa0c16da
https://hg.mozilla.org/mozilla-central/rev/c5edac4ccac9
https://hg.mozilla.org/mozilla-central/rev/016f24de0fa3