The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8

commit 4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8
Author: Philip Rogers <pdr@chromium.org>
Date: Tue Oct 24 19:29:40 2017

Remove inert visual viewport setting

The inert visual viewport feature has shipped so we can remove
this setting. This will make it easier to develop features such
as root layer scrolling.

Bug:  489206 ,  774711 
Change-Id: Ia007c0712eda14b658cfbe7a90402c0a45c305b7
Reviewed-on: https://chromium-review.googlesource.com/733800
Commit-Queue: Philip Rogers <pdr@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Justin Novosad <junov@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#511233}
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/LayoutTests/fast/scroll-behavior/main-frame-pinch-scrolls-layout-viewport.html
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/LayoutTests/fast/scroll-behavior/scroll-into-view-scrolls-layout-viewport.html
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/core/dom/Element.cpp
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/core/frame/Settings.json5
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/core/frame/VisualViewport.cpp
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
[modify] https://crrev.com/4380beb4e7b1f9339e86c5ad1e41b5ae87ba52c8/third_party/WebKit/Source/modules/canvas/canvas2d/CanvasRenderingContext2D.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a8e1de5b19353797ee41b343d1e4cc021d61d735

commit a8e1de5b19353797ee41b343d1e4cc021d61d735
Author: Philip Rogers <pdr@chromium.org>
Date: Wed Oct 25 19:35:10 2017

[root layer scrolls] Make VisualViewport size RLS-aware

This patch makes VisualViewport.{width, height} work with
root layer scrolling (RLS) where the layout viewport
scrollable area should be used to access the visible
content rect. 

This patch removes the scrollbar size codepath from
LocalDomWindow so it is only used by inner{width, height}
and can return the LocalFrameView's size without a layout
in many cases. The scrollbar size codepaths in VisualViewport
and DOMVisualViewport have been updated to use the correct
visible content rect.

With this patch, 11 more tests pass with RLS.

Bug:  774711 
Change-Id: Idc2357fe12767bda6b3e0d94006141bf265203fd
Reviewed-on: https://chromium-review.googlesource.com/729467
Reviewed-by: Stefan Zager <szager@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#511555}
[modify] https://crrev.com/a8e1de5b19353797ee41b343d1e4cc021d61d735/third_party/WebKit/LayoutTests/FlagExpectations/root-layer-scrolls
[modify] https://crrev.com/a8e1de5b19353797ee41b343d1e4cc021d61d735/third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp
[modify] https://crrev.com/a8e1de5b19353797ee41b343d1e4cc021d61d735/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
[modify] https://crrev.com/a8e1de5b19353797ee41b343d1e4cc021d61d735/third_party/WebKit/Source/core/frame/LocalDOMWindow.h
[modify] https://crrev.com/a8e1de5b19353797ee41b343d1e4cc021d61d735/third_party/WebKit/Source/core/frame/VisualViewport.cpp