February 2021: New Features, Testing, Stability Fixes, Code Health and more!

<td><td>Document has some global state for display locks.</td></td>

<td><td>Added time of last lock update</td></td>

<td><td>Use time of last lock update to determine if locally cached lock
state is stale.</td></td>

<td><td>Unblocks remaining steps in developing the feature. (<a
href="https://docs.google.com/document/d/1Enj8nD-y2vgCp2A6-M2QFoUKf1-nxMX023ervOoXi50/edit?usp=sharing">Design
doc</a>)</td></td>

<td><td>The first finch study had a lot of crashes, xidachen@ <a
href="https://chromium-review.googlesource.com/c/chromium/src/+/2675160">landed</a>
fix for that.</td></td>

<td><td>The second finch try crashed a small number of users, xidachen@ <a
href="https://chromium-review.googlesource.com/c/chromium/src/+/2692609">landed</a>
fix.</td></td>

<td><td>Currently, there are two known problems, and we are actively working
to resolve them.</td></td>

<td><td>Here is a <a
href="https://docs.google.com/document/d/1iz0YdNKHpcObTe3UrM7uY6fsGv8xOlwY35m5dZzIoR8/edit">doc</a>
that describes how to detect different types of main-thread animations from
traces. And here is a sample <a
href="https://drive.google.com/file/d/1IdObZMCYRMraUIYcM5RSQo2L9u2Uhqw9/view?usp=sharing&resourcekey=0-rTeQ2zu0ajWxMtGGhFAKng">video</a>
of output.</td></td>

<td><td>Bug hunting - no bugs identified.</td></td>

<td><td>Expanded finch experiment to 10% stable.</td></td>

<td><td>Landed Accessibility click <a
href="https://chromium-review.googlesource.com/c/chromium/src/+/2679278">CL</a>,
part of which was relevant to Click as pointer event.</td></td>

Content-visible CSS animations & transitions

kevers@ has been working on this feature and fixed some problems.

Problem 1: Wasteful to run animations on hidden content (content-visibility hidden or auto + offscreen).

Problem 2: Wasteful to check each frame if the conditions apply.

Solution:

Composite background-color animation

xidachen@ landed some CLs to complete the implementation for this feature, and then started a finch experiment.

Animation Validation

xidachen@ worked on validating main-thread animation detection logic, as part of the core web-vitals effort.

Impulse animations

flackr@ supported arakeri@microsoft.com to implement this feature, which has a faster initial impulse when scrolling. This is shipped in M90.

Click/Auxclick as pointer event

liviutinta@ made some great progress in this sprint.

<td><td>Added pointer events up/down.</td></td>

<td><td>Populated mouse events coordinates appropriately.</td></td>

<td><td>Cleaned up the code by using SimulatedClickCreationScope as argument
for <a
href="https://source.chromium.org/chromium/chromium/src/+/HEAD:third_party/blink/renderer/core/dom/element.h;drc=763c071aa91f87c5e404edff98bc5bac8075d4a1;l=600">Element::AccessKeyAction</a>
instead of bool send_mouse_events to clarify where the simulated click
originates from</td></td>

<td><td>Added wpt tests for clicks from accesskey and clicks from
enter/space keys to ensure interop</td></td>

<td><td>In the code shown above, the Create() function does more than what
the name applies!</td></td>

<td><td>Regression has been fixed, a test has been added.</td></td>

	Tabs		girard@ started this Tabs One-Pager, and a lot of people are contributing to it now.		flackr@ and nsull@ took a first pass at an explainer.		Disable double tap to zoom for mobile viewport		liuviutinta@ has a CL in review, and still working on writing tests for Andriod.
	Accessibility click indistinguishable from real click		liviutinta@ landed a CL to fix this bug. The fix included:		Pointer lock: pointerrawupdate coordinate jumps				musta@ discovered a regression due to a code “improvement”.