Reland: Onion-soupify blink leak detector

Original patch exposed an issue in layout test controller, which was
fixed by https://chromium-review.googlesource.com/c/chromium/src/+/1015221.

> Onion-soupify blink leak detector
>
> - Expose LeakDetector interface in render process, remove unneeded plumbing.
> - Switch from IPCs to Mojo in layout test runner.
> - Move implementation to controller.
> - Migrate inspector usage to browser.
> - Merged two methods of LeakDetector into a single one.
> - Fixed leaks in existing tests.
>
> Needs a followup to not register fetchers in leak detector,
> but instead have a collection in ResourceFetcher.
>
> Reviewed-on: https://chromium-review.googlesource.com/999170
> Reviewed-by: Maxim Kolosovskiy <kolos@chromium.org>
> Reviewed-by: Yuzu Saijo <yuzus@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#551012}

TBR=kolos,yuzus,dcheng,haraken
NOPRESUBMIT=true

Bug: 833609
Change-Id: I6723ffc4aa6a88e6d6d88cc3850410dcd42aa51c
Reviewed-on: https://chromium-review.googlesource.com/1016021
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552228}
46 files changed