This CL moves us much closer to the point where we can remove debugger-script.js and usage of debugger context from inspector.
There are three main parts left:
- managing breakpoints,
- inspecting stack and scopes (this CL),
- LiveEdit.

In this CL I moved all stack/scope inspection to native. As side effect running debugger and inspector tests are 10-20% faster (it's significant since not all of tests requesting break).

R=yangguo@chromium.org,jgruber@chromium.org

Bug: chromium:652939
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I409396a687e18e9c0554c0c9c35b6e1064627be8
Reviewed-on: https://chromium-review.googlesource.com/580645Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46947}