[puLL-Merge] - brave/brave-core@34207

Description

This PR redesigns the search widget promotion panel in the Brave Android browser with several key improvements:

1. UI Redesign: The search widget promo panel is completely redesigned — replacing the old horizontal icon+text layout with a centered card that includes a visual preview of the actual search widget (search bar with microphone, private search, and Leo icons), centered title/description text, and side-by-side "Not now" / "Add widget" buttons.

2. Popup positioning improvements: The promo panel now displays at the bottom of the screen (using Gravity.BOTTOM) instead of as a dropdown from the URL bar, accounting for bottom toolbar height and navigation bar insets. It also handles orientation changes and keyboard open/close events properly.

3. Source tracking for widget searches: When a search originates from the search widget, the source=android query parameter on search.brave.com URLs is rewritten to source=android-widget for analytics differentiation.

4. Onboarding activity finish race fix: The WelcomeOnboardingActivity now waits for the next activity to resume (or itself to stop) before finishing, preventing visual glitches on foldable devices during task transitions.

5. Tablet/foldable layout improvements: Adds height-bucketed dimension resources for onboarding card margins on tablets in portrait mode, and makes heading font weights bolder/consistent.

6. Cleanup: Removes unused drawables (ic_search_widget_promotion_icon.xml, ic_widget_generic.xml, add_widget_button.xml), removes unnecessary Build.VERSION.SDK_INT checks (minSdk is already >= O), and removes the button_background_widget_promo color.

Possible Issues

• Copyright year typo: Multiple new files have Copyright (c) 2026 in the header instead of 2025. This appears in button_transparent.xml, rounded_surface_container_background.xml, widget_promo_panel_search_background.xml, widget_search_preview.xml, BraveIntentHandlerUnitTest.java, and all new dimens files.

• HeadingH3 style change is global: Changing heading_h3 from 22sp to 20sp and fontWeight from 500 to 600 affects every use of HeadingH3 style across the app, not just onboarding. This could cause unintended visual regressions elsewhere.

• Race condition in launchPendingIntentAndFinish: If neither condition triggers (the current activity never reaches STOPPED/DESTROYED and no other activity resumes), the ActivityStateListener would leak and the activity would never finish. This seems unlikely but is theoretically possible in edge cases.

• Promo panel re-shown on night mode change: In onDestroyInternal, the code writes SHOULD_SHOW_SEARCH_WIDGET_PROMO = true back to preferences if the promo was showing. However, the showIfNeeded path also writes it to false. This could cause the promo to persist across multiple configuration changes indefinitely until the user explicitly dismisses it.

• PopupWindow focus steals touch: The PopupWindow is created with focusable = true, which may intercept back presses and touch events outside the popup in unexpected ways.

Security Hotspots

• URL rewriting in maybeReplaceWidgetSearchSource: The method rebuilds the URL by iterating query parameters and reconstructing them. While the logic appears sound (only modifying source=android → source=android-widget on search.brave.com), any URL parsing/reconstruction is sensitive. The use of Uri.parse() on untrusted intent data is standard Android practice but worth noting.

sequenceDiagram
    participant User
    participant BraveActivity
    participant SearchWidgetPromoPanel
    participant PopupWindow
    participant BraveIntentHandler
    participant SearchWidget

    Note over BraveActivity: URL bar focused, promo flag is true
    BraveActivity->>SearchWidgetPromoPanel: new SearchWidgetPromoPanel()
    BraveActivity->>BraveActivity: showWidgetPromoPanel()
    BraveActivity->>SearchWidgetPromoPanel: showIfNeeded(rootView, bottomOffset, context)
    SearchWidgetPromoPanel->>PopupWindow: new PopupWindow(view)
    SearchWidgetPromoPanel->>PopupWindow: showAtLocation(Gravity.BOTTOM)

    alt User taps "Add widget"
        User->>SearchWidgetPromoPanel: onClick(btAddWidget)
        SearchWidgetPromoPanel->>SearchWidget: requestPinAppWidget()
        SearchWidgetPromoPanel->>PopupWindow: dismiss()
    else User taps "Not now"
        User->>SearchWidgetPromoPanel: onClick(tvNotNow)
        SearchWidgetPromoPanel->>PopupWindow: dismiss()
    else Keyboard opens
        BraveActivity->>BraveActivity: onKeyboardOpened()
        BraveActivity->>SearchWidgetPromoPanel: dismiss()
    else Orientation changes
        BraveActivity->>BraveActivity: onOrientationChange()
        BraveActivity->>SearchWidgetPromoPanel: showIfNeeded() (reposition)
    end

    Note over SearchWidget: User searches via widget
    SearchWidget->>BraveIntentHandler: Intent with EXTRA_FROM_SEARCH_WIDGET
    BraveIntentHandler->>BraveIntentHandler: extractUrlFromIntent()
    BraveIntentHandler->>BraveIntentHandler: maybeReplaceWidgetSearchSource()
    Note over BraveIntentHandler: source=android → source=android-widget

📋 Code Owners Summary

35 file(s) changed, 18 with assigned owners

2 team(s) affected: @brave/Android, @brave/string-reviewers-team

Owners and Their Files

@brave/Android — 17 file(s)

• android/java/res/values-night/brave_colors.xml
• android/java/res/values/brave_colors.xml
• android/java/res/values/brave_dimens.xml
• browser/first_run/android/java/res/layout-sw600dp-land/block_interruptions.xml
• browser/first_run/android/java/res/layout-sw600dp-land/help_brave_search.xml

@brave/string-reviewers-team — 1 file(s)

• browser/ui/android/strings/android_brave_strings.grd