2062212 - [MCAB HNT] Phase 6: Enable new tab search bar in Nightly

Status: RESOLVED FIXED

(Firefox :: Address Bar, task, P2)

Description

[Dão Gottwald [:dao]]

Part of the MCAB HNT roadmap: putting <moz-urlbar> on the Home / New Tab page.

Roll out the newtab <moz-urlbar> through browser.urlbar.newtab.featureGate in two stages: a build-time default flip for Nightly, then a remote Nimbus recipe for the ramp to release. Blocked on the end-to-end tests being green and the styling being correct.

a. Nightly-on by default. Replace the flat false default in firefox.js with an #ifdef NIGHTLY_BUILD override, keeping the PREF_URLBAR_DEFAULTS map entry false as the release fallback (the browser.urlbar.autoFill.adaptiveHistory.enabled precedent). Done when Nightly shows the newtab <moz-urlbar> by default and release/beta still show the handoff bar.

b. Wire the gate to Nimbus. Add a variable under the urlbar feature in toolkit/components/nimbus/FeatureManifest.yaml with fallbackPref: browser.urlbar.newtab.featureGate, following the *.featureGate fallbackPref pattern already used there. UrlbarPrefs resolves the Nimbus value over the pref default, so no read-side wiring is needed. Confirm the variable name doesn't collide with an existing urlbar feature variable.

c. Author the Nimbus rollout recipe. With the gate remotely controllable, author a rollout in Experimenter targeting release users -- a staged percentage ramp, reversible by disabling the rollout. The build-time #ifdef stays Nightly-only so release safety doesn't depend on the recipe staying live.

Comment 1

[Dão Gottwald [:dao]]

Attachment: Bug 2062212 - Enable new tab search bar in Nightly. r?mbeier!

Not ready to land: the end-to-end tests and the styling have to be there first. The PREF_URLBAR_DEFAULTS entry stays false, so a build without the pref still reads the gate as off.

Comment 2

[Dão Gottwald [:dao]]

Attachment: Bug 2062212 - Turn the newtab feature gate off in the tests that drive the handoff bar. r?daleharvey!,#search-reviewers!

The next commit makes the gate default on for Nightly, which supersedes the handoff bar and leaves these tests waiting for markup that is no longer there.

Comment 3

[Dão Gottwald [:dao]]

Attachment: Bug 2062212 - Put the newtab feature gate under Nimbus control. r?daleharvey!

The pref becomes the variable's fallback, so both registrants read newtabFeatureGate instead: a raw pref read does not see an enrollment.

Comment 4

[Phabricator Automation]

Comment on attachment 9630479 [details]
Bug 2062212 - Put the newtab feature gate under Nimbus control. r?daleharvey!

Revision D321164 was moved to bug 2066752. Setting attachment 9630479 [details] to obsolete.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a8ca1eac0bb4
https://hg.mozilla.org/integration/autoland/rev/540bd3cda62f
Turn the newtab feature gate off in the tests that drive the handoff bar. r=daleharvey,search-reviewers,urlbar-reviewers

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/59854278ebab
https://hg.mozilla.org/integration/autoland/rev/70ae344e0fd3
Enable new tab search bar in Nightly. r=mbeier

Comment 7

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/540bd3cda62f
https://hg.mozilla.org/mozilla-central/rev/70ae344e0fd3

Comment 8

[Dão Gottwald [:dao]]

Release Note Request (optional, but appreciated)
[Why is this notable]:
[Affects Firefox for Android]:
[Suggested wording]: The search bar on the new tab is a real search bar now, showing results on the page instead of sending you to the address bar.
[Links (documentation, blog post, etc)]:

Comment 9

[Donal Meehan [:dmeehan]]

Added to the Fx156 nightly release notes, please allow 30 minutes for the site to update.
The nightly-only note will be removed after three cycles or when it is enabled by default, whichever comes earlier.

Comment 10

[Performance Sheriff Bot]

Perfherder has detected a talos performance change from push 70ae344e0fd37807d3806e937d9ea8490045fbbf.

No action is required from the author; this comment is provided for informational purposes only.

Improvement	Test	Platform	Options	Absolute values [old vs new]
7%	tart (doc)	linux2404-64-shippable	e10s fission stylo webrender-sw	2.64 -> 2.45
7%	tart (doc)	linux2404-64-shippable	e10s fission stylo webrender	2.41 -> 2.24

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Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests.