The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/522668edcb832f3d00859d387485406c614df521

commit 522668edcb832f3d00859d387485406c614df521
Author: Gauthier Ambard <gambard@chromium.org>
Date: Wed Jan 03 15:47:45 2018

Add named layout guide for the toolbar's bubbles

The bubble tips are presented with an anchor point to know where the
tip of the arrow should be positioned.
A delegate was used to get this point.
This CL changes it to a named layout guide for the clean toolbar.
The named layout guide can't be used with the old toolbar as it is not
positioned with auto-layout internally.

Bug:  788371 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Idbca4372faa2738a65161112d0a4ec59c17e3b36
Reviewed-on: https://chromium-review.googlesource.com/848894
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526701}
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/bubble/bubble_view_anchor_point_provider.h
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/clean/BUILD.gn
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/clean/toolbar_coordinator.h
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/clean/toolbar_coordinator.mm
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/clean/toolbar_view_controller.h
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/clean/toolbar_view_controller.mm
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/toolbar/toolbar_adapter.mm
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/util/BUILD.gn
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/util/named_guide.h
[modify] https://crrev.com/522668edcb832f3d00859d387485406c614df521/ios/chrome/browser/ui/util/named_guide.mm

Fixing this as the bubble tips are using named layout guide for positioning themselves. We could expand it by having the position be using more autolayout, but it will probably be fixed with the UI refresh as the bubbles need to be shown for top and bottom toolbars' buttons.