The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/246d85666a151d26eac19f9e910dcb4766239355

commit 246d85666a151d26eac19f9e910dcb4766239355
Author: Ehsan Karamad <ekaramad@chromium.org>
Date: Fri Dec 21 00:14:12 2018

FeaturePolicy: Count potential feature violations

This CL introduces a new enumeration metric for feature policies,
namely, "PotentialViolation". This new metric tracks potential
violations of each feature policy in a document; that is, for
feature policy X this metric would emit a potential violation if
the conditions to violate feature X are (regardless of the actual
feature X being disabled in the document). In other words, the
metric tracks the percentage of pages that would have violated the
given feature X if it was disabled in all documents.

Most current policies are covered by this CL. The few cases where a
policy generates its own violation report, or does not support
reporting violations yet, will be addressed in future CLs.

Bug: 915788
Change-Id: Iccb77ee8f47995a0debe7bb1faafbee3686b2ed6
Reviewed-on: https://chromium-review.googlesource.com/c/1380933
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618394}
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/third_party/blink/renderer/core/dom/document.cc
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/third_party/blink/renderer/core/dom/document.h
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/third_party/blink/renderer/core/execution_context/security_context.cc
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/third_party/blink/renderer/core/execution_context/security_context.h
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/third_party/blink/renderer/core/feature_policy/feature_policy_test.cc
[modify] https://crrev.com/246d85666a151d26eac19f9e910dcb4766239355/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ce1cf8f2550d9515afa693efbb08e4ad6062908e

commit ce1cf8f2550d9515afa693efbb08e4ad6062908e
Author: Ehsan Karamad <ekaramad@chromium.org>
Date: Thu Jan 17 00:47:39 2019

[ FeaturePolicy ] - Potential violations for "unsized-media"

This CL adds the logic to support counting potential violations of "unsized-media"
feature (Blink.UseCounter.FeaturePolicy.PotetialViolation).

Bug: 915788
Change-Id: I523f8e4cd7dca4d640fd8c8c22b0e86c058bce99
Reviewed-on: https://chromium-review.googlesource.com/c/1409803
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623468}
[modify] https://crrev.com/ce1cf8f2550d9515afa693efbb08e4ad6062908e/third_party/blink/renderer/core/html/media/media_element_parser_helpers.cc
[modify] https://crrev.com/ce1cf8f2550d9515afa693efbb08e4ad6062908e/third_party/blink/renderer/core/html/media/media_element_parser_helpers.h
[modify] https://crrev.com/ce1cf8f2550d9515afa693efbb08e4ad6062908e/third_party/blink/renderer/core/layout/layout_image.cc
[modify] https://crrev.com/ce1cf8f2550d9515afa693efbb08e4ad6062908e/third_party/blink/renderer/core/layout/layout_video.cc
[modify] https://crrev.com/ce1cf8f2550d9515afa693efbb08e4ad6062908e/third_party/blink/renderer/core/layout/svg/layout_svg_image.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ad1066ce0df586d19daf9e43942db479a71a687c

commit ad1066ce0df586d19daf9e43942db479a71a687c
Author: Ehsan Karamad <ekaramad@chromium.org>
Date: Fri Jan 18 16:52:55 2019

[ FeaturePolicy ] Potential violation for "layout-animation"

This CL adds the logic to track potential violations for the
"layout-animations" feature
(Blink.UseCounter.FeaturePolicy.PotentialViolation).

This CL counts all potential violations through CSS keyframes or use of
element.animate() API. Similar to the real reporting for this policy,
"transitions" are currently excluded (will be added in future CLs).

Bug: 915788
Change-Id: I94e3356469ba4e65569c39f7a40592663ad8b0ae
Reviewed-on: https://chromium-review.googlesource.com/c/1389024
Reviewed-by: Robert Flack <flackr@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624164}
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/animation/element_animation.cc
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/css/parser/css_parser_context.cc
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/css/parser/css_parser_context.h
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/css/parser/css_parser_impl.cc
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/exported/web_view_test.cc
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/feature_policy/layout_animations_policy.cc
[modify] https://crrev.com/ad1066ce0df586d19daf9e43942db479a71a687c/third_party/blink/renderer/core/feature_policy/layout_animations_policy.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3488b4555d7bbe8777426b38fabaeecd248ae470

commit 3488b4555d7bbe8777426b38fabaeecd248ae470
Author: Ehsan Karamad <ekaramad@chromium.org>
Date: Mon Jan 21 20:58:50 2019

[ FeaturePolicy ] - Report for "legacy-image-formats"

This CL adds support for generating reports for violations of the
"legacy-image-formats" feature policy. This also automatically starts
counting the potential violations of this feature in web pages
(Blink.UseCounter.FeaturePolicy.PotentialViolation).

Bug: 915788
Change-Id: If72ec438b6038730907ac086bddd0c680cc60d97
Reviewed-on: https://chromium-review.googlesource.com/c/1409698
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Ehsan Karamad <ekaramad@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624657}
[modify] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/renderer/core/layout/layout_image.cc
[add] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/web_tests/external/wpt/feature-policy/reporting/image.bmp
[add] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/web_tests/external/wpt/feature-policy/reporting/legacy-image-formats-reporting.html
[add] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/web_tests/external/wpt/feature-policy/reporting/legacy-image-formats-reporting.html.headers
[add] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/web_tests/http/tests/images/feature-policy-image-policies-with-border-radius-expected.txt
[add] https://crrev.com/3488b4555d7bbe8777426b38fabaeecd248ae470/third_party/blink/web_tests/http/tests/images/feature-policy-legacy-formats-expected.txt