The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4861f459e4e929f0956b408ad89745be47dd22ca

commit 4861f459e4e929f0956b408ad89745be47dd22ca
Author: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Date: Mon Sep 10 15:32:04 2018

[BrowserSwitcher] Add BrowserSwitcherService{,Factory}

BrowserSwitcherService is a per-BrowserContext class that manages
resources that should be shared between tabs in the same BrowserContext:
for now, the sitelist and browser launcher objects.

The BrowserSwitcherServiceFactory lets us easily create only one
BrowserSwitcherService per BrowserContext.

Bug:  876803 
Change-Id: I6eb4c235143cfe38a077141b62e9332ed0f30a05
Reviewed-on: https://chromium-review.googlesource.com/1206698
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Commit-Queue: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589922}
[modify] https://crrev.com/4861f459e4e929f0956b408ad89745be47dd22ca/chrome/browser/BUILD.gn
[add] https://crrev.com/4861f459e4e929f0956b408ad89745be47dd22ca/chrome/browser/browser_switcher/browser_switcher_service.cc
[add] https://crrev.com/4861f459e4e929f0956b408ad89745be47dd22ca/chrome/browser/browser_switcher/browser_switcher_service.h
[add] https://crrev.com/4861f459e4e929f0956b408ad89745be47dd22ca/chrome/browser/browser_switcher/browser_switcher_service_factory.cc
[add] https://crrev.com/4861f459e4e929f0956b408ad89745be47dd22ca/chrome/browser/browser_switcher/browser_switcher_service_factory.h