Build URL:
==========
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/win64%20beta/builds/1146
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/win64%20beta/builds/1147

https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/mac64%20beta/builds/1357
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/mac64%20beta/builds/1358

https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/linux64%20beta/builds/1394
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/linux64%20beta/builds/1395

Log URL:
=========
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/win64%20beta/builds/1146/steps/compile/logs/stdio
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/win64%20beta/builds/1147/steps/compile/logs/stdio

https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/mac64%20beta/builds/1357/steps/compile/logs/stdio
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/mac64%20beta/builds/1358/steps/compile/logs/stdio

https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/linux64%20beta/builds/1394/steps/compile/logs/stdio
https://uberchromegw.corp.google.com/i/official.desktop.continuous/builders/linux64%20beta/builds/1395/steps/compile/logs/stdio

Content from the Log:
=====================
FAILED: obj/third_party/WebKit/Source/core/dom/dom_1/Document.obj 
ninja -t msvc -e environment.x64 -- "c:\b\c\win_toolchain\vs_files\f53e4598951162bad6330f7a167486c7ae5db1e5\vc\bin\amd64/cl.exe" /nologo /showIncludes  @obj/third_party/WebKit/Source/core/dom/dom_1/Document.obj.rsp /c ../../third_party/WebKit/Source/core/dom/Document.cpp /Foobj/third_party/WebKit/Source/core/dom/dom_1/Document.obj /Fd"obj/third_party/WebKit/Source/core/dom/dom_1_cc.pdb"
../../third_party/WebKit/Source/core/dom/Document.cpp(5835): error C2039: 'OwnerDocument': is not a member of 'blink::DocumentInit'
C:\b\c\b\win64_beta\src\third_party\WebKit\Source\core/loader/DocumentLoader.h(63): note: see declaration of 'blink::DocumentInit'
../../third_party/WebKit/Source/core/dom/Document.cpp(5843): error C2039: 'OwnerDocument': is not a member of 'blink::DocumentInit'
C:\b\c\b\win64_beta\src\third_party\WebKit\Source\core/loader/DocumentLoader.h(63): note: see declaration of 'blink::DocumentInit'

Suspecting below change could be a possible culprit.

https://chromium.googlesource.com/chromium/src/+/cb54da8199ba125d94cfcdd8edec14bef1ce3cf1

@andypaicu: Assigning to you, kindly take a look into it. Please help us to find an owner if not with respect to your change. We have scheduled Beta release tomorrow. Tagging wth beta blocker.