The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/39e402647a842f4fcc12faded11d486aca8eda47

commit 39e402647a842f4fcc12faded11d486aca8eda47
Author: tkent <tkent@chromium.org>
Date: Mon Mar 14 06:06:47 2016

Add three UseCounters for LABEL element.

HTMLLabelElementFormIsDifferentFromControlForm:
HTMLLabelElementHasNoControlAndFormIsAncestor:
  They are for label[form] deprecation.
  https://github.com/whatwg/html/issues/787

HTMLLabelElementControlForNonFormAssociatedElement
  This is for a LABEL with PROGRESS or METER.
  This is counted on any LABEL-specific behaviors.
  e.g.  |form| IDL access, |control| IDL access, Clicking a LABEL, etc.

This CL has no user-visible behavior changes.

BUG= 594447 
TBR=isherman@chromium.org

Review URL: https://codereview.chromium.org/1790143004

Cr-Commit-Position: refs/heads/master@{#380933}

[modify] https://crrev.com/39e402647a842f4fcc12faded11d486aca8eda47/third_party/WebKit/Source/core/frame/UseCounter.h
[modify] https://crrev.com/39e402647a842f4fcc12faded11d486aca8eda47/third_party/WebKit/Source/core/html/HTMLLabelElement.cpp
[modify] https://crrev.com/39e402647a842f4fcc12faded11d486aca8eda47/third_party/WebKit/Source/core/html/HTMLLabelElement.h
[modify] https://crrev.com/39e402647a842f4fcc12faded11d486aca8eda47/third_party/WebKit/Source/core/html/HTMLLabelElement.idl
[modify] https://crrev.com/39e402647a842f4fcc12faded11d486aca8eda47/tools/metrics/histograms/histograms.xml

Your change meets the bar and is auto-approved for M50 (branch: 2661)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e1c470bb537ac2c1fe83e8c1f6b3719782033ed9

commit e1c470bb537ac2c1fe83e8c1f6b3719782033ed9
Author: Kent Tamura <tkent@chromium.org>
Date: Tue Mar 15 07:54:41 2016

Add three UseCounters for LABEL element.

HTMLLabelElementFormIsDifferentFromControlForm:
HTMLLabelElementHasNoControlAndFormIsAncestor:
  They are for label[form] deprecation.
  https://github.com/whatwg/html/issues/787

HTMLLabelElementControlForNonFormAssociatedElement
  This is for a LABEL with PROGRESS or METER.
  This is counted on any LABEL-specific behaviors.
  e.g.  |form| IDL access, |control| IDL access, Clicking a LABEL, etc.

This CL has no user-visible behavior changes.

BUG= 594447 
TBR=isherman@chromium.org

Review URL: https://codereview.chromium.org/1790143004

Cr-Commit-Position: refs/heads/master@{#380933}
(cherry picked from commit 39e402647a842f4fcc12faded11d486aca8eda47)

Review URL: https://codereview.chromium.org/1802263002 .

Cr-Commit-Position: refs/branch-heads/2661@{#236}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}

[modify] https://crrev.com/e1c470bb537ac2c1fe83e8c1f6b3719782033ed9/third_party/WebKit/Source/core/frame/UseCounter.h
[modify] https://crrev.com/e1c470bb537ac2c1fe83e8c1f6b3719782033ed9/third_party/WebKit/Source/core/html/HTMLLabelElement.cpp
[modify] https://crrev.com/e1c470bb537ac2c1fe83e8c1f6b3719782033ed9/third_party/WebKit/Source/core/html/HTMLLabelElement.h
[modify] https://crrev.com/e1c470bb537ac2c1fe83e8c1f6b3719782033ed9/third_party/WebKit/Source/core/html/HTMLLabelElement.idl