Fix search-only omnibar margin leaking onto the Duck.ai input

[YoussefKeyrouz]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1212810093780571/task/1217145379104435?focus=true
Tech Design URL (if applicable):
API Proposals URL(s) (if applicable):

Description

In search-only address-bar mode, the Duck.ai input field showed an extra ~16dp gap on its leading (start) side. The native input's shared card was picking up the browser omnibar's start margin and keeping it when the same widget re-rendered as the Duck.ai input.applyOmnibarShape() sets the browser omnibar's margin on the shared input card, but had no reset path when shared with other places.

Fix:
In applyOmnibarShape():

• The else branch now resets marginStart to its resting value (0) for any non-omnibar state, so the margin can't leak onto the shared Duck.ai card.

Test the omnibar in each location (top, bottom, split) in Search only mode:

• Browser omnibar: on the NTP or a loaded page, focus the omnibar. The native input opens with the correct omnibar shape
• Duck.ai input (the fix): open/load Duck.ai. The input field's leading margin is correct (no extra ~16dp gap between the leading edge and the field)
• Unfocus the Native field in duck.ai, no gaps between the field and the fire button

Regression spot-checks

• Contextual Duck.ai sheet : No impact on look.
• Search _ Duck.ai mode: No impact on look.

UI changes

Before	After

---

Note

Low Risk
Localized UI layout logic in NativeInputModeWidget with no auth, data, or API changes; risk is limited to omnibar/Duck.ai card positioning regressions.

Overview
Fixes search-only omnibar horizontal margin leaking onto the shared Duck.ai input card when both widgets observe the same per-tab state.

applyOmnibarShape() no longer exits early for non-browser, bottom, or toggle-visible states. It now applies the wide top search-only browser shape (radius + margins) only when BROWSER, toggle hidden, and not bottom; every other state clears marginStart on the parent MaterialCardView so omnibar margins don’t stick on Duck.ai layouts. Layout params are always updated after that branch.

^{Reviewed by Cursor Bugbot for commit d8e7328. Bugbot is set up for automated code reviews on this repo. Configure here.}

[YoussefKeyrouz]

• Fix search-only omnibar margin leaking onto the Duck.ai input #9409 👈 (View in Graphite)
• develop

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[malmstein]

Nice work, thanks @YoussefKeyrouz !