The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f790e0fe01a375cd4209713e4b7efe00b6076dfc

commit f790e0fe01a375cd4209713e4b7efe00b6076dfc
Author: Yuta Kitamura <yutak@chromium.org>
Date: Tue Mar 20 08:55:44 2018

Simplify initialization sequence of WebFrameScheduler.

Currently, WebFrameScheduler is created through ChromeClient, but
actually we don't have to talk to ChromeClient -- we can directly
get PageScheduler from Page, and then call PageScheduler::
CreateFrameScheduler().

Bug:  822201 
Change-Id: Ib4c85a41a18f2e2deb8f2a8a96aa527c6f5b4cbe
Reviewed-on: https://chromium-review.googlesource.com/964072
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Yuta Kitamura <yutak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544312}
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/frame/LocalFrame.cpp
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/loader/EmptyClients.cpp
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/loader/EmptyClients.h
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/page/ChromeClient.h
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/page/ChromeClientImpl.cpp
[modify] https://crrev.com/f790e0fe01a375cd4209713e4b7efe00b6076dfc/third_party/WebKit/Source/core/page/ChromeClientImpl.h