The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/950384ffd4e30b1912c088d020e01794e78e98fa

commit 950384ffd4e30b1912c088d020e01794e78e98fa
Author: Darren Shen <shend@chromium.org>
Date: Tue Feb 20 04:59:09 2018

[css-typed-om] Implement StylePropertyMap.clear.

This patch adds the clear() method to inline & declared StylePropertyMap
Spec: https://drafts.css-houdini.org/css-typed-om-1/#dom-stylepropertymap-clear

Bug:  813653 
Change-Id: Ib56f60fa59dc8d241e7fb1a7695fce2bea094026
Reviewed-on: https://chromium-review.googlesource.com/925761
Commit-Queue: Darren Shen <shend@chromium.org>
Reviewed-by: nainar <nainar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537717}
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/LayoutTests/external/wpt/css/css-typed-om/interfaces-expected.txt
[add] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/LayoutTests/external/wpt/css/css-typed-om/the-stylepropertymap/declared/clear.html
[add] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/LayoutTests/external/wpt/css/css-typed-om/the-stylepropertymap/inline/clear.html
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/LayoutTests/external/wpt/interfaces/css-typed-om.idl
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/DeclaredStylePropertyMap.cpp
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/DeclaredStylePropertyMap.h
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/InlineStylePropertyMap.cpp
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/InlineStylePropertyMap.h
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/StylePropertyMap.cpp
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/StylePropertyMap.h
[modify] https://crrev.com/950384ffd4e30b1912c088d020e01794e78e98fa/third_party/WebKit/Source/core/css/cssom/StylePropertyMap.idl