The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/efae5114048daf81d68408806e5b3c4bb95a0de6

commit efae5114048daf81d68408806e5b3c4bb95a0de6
Author: Stephen McGruer <smcgruer@chromium.org>
Date: Thu Jul 27 12:28:02 2017

devtools: Add position:sticky constraint information to Layers panel

The information contained in WebStickyPositionConstraints is useful for
investigating sticky bugs and for explaining sticky to Chromium and web
developers alike. For example, the added information here will let a web
developer know quickly if they have made their containing block too
small for the sticky element to shift - a common oversight that
developers make.

BUG=730656

Change-Id: I5b9e95e189517a4783740cbdac292554d97fcf76
Reviewed-on: https://chromium-review.googlesource.com/553598
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489905}
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/http/tests/inspector/inspector-test.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/http/tests/inspector/layers-test.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/inspector-protocol/layers/get-layers-expected.txt
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/inspector-protocol/layers/get-layers.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/inspector-protocol/resources/get-layers.html
[add] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/inspector/layers/layer-sticky-position-constraint-get-expected.txt
[add] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/LayoutTests/inspector/layers/layer-sticky-position-constraint-get.html
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/core/inspector/InspectorLayerTreeAgent.cpp
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/core/inspector/browser_protocol.json
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/devtools/front_end/layer_viewer/LayerDetailsView.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/devtools/front_end/layers/LayerTreeModel.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/devtools/front_end/sdk/LayerTreeBase.js
[modify] https://crrev.com/efae5114048daf81d68408806e5b3c4bb95a0de6/third_party/WebKit/Source/devtools/front_end/timeline_model/TracingLayerTree.js

No further work is currently being done on sticky; however keeping this around as we may want to add tracing in the future.