Web Apps Shared Component (`components/webapps`)

This directory contains features and logic for Web Applications (Progressive Web Apps) that are shared between different platforms (primarily Android and Desktop).

For platform-specific implementations and orchestrations, see:

Desktop Web Apps (chrome/browser/web_applications)
Android Web Apps (WebAPKs and TWAs) Architecture
Web Apps Core Concepts - Universal and cross-platform Progressive Web App documentation.

Key Subsystems

1. Installability Detection (`browser/installable/`)

The InstallableManager is responsible for checking if a website is installable as a Progressive Web App. It verifies:

Presence and validity of a Web App Manifest.
Service worker registration (if required).
Icon requirements.
Other installability criteria.

See header files for details:

InstallableManager - Main entry point to schedule installability checks.
InstallableData - Structure containing the results of the check.

2. App Banners and Promotion (`browser/banners/`)

The AppBannerManager decides when and how to promote PWA installation to the user (e.g., showing an install icon in the omnibox, an ambient badge, or a bottom sheet). It uses InstallableManager to check eligibility and tracks user engagement to avoid spamming.

See header files for details:

AppBannerManager - Base class for managing banner visibility and triggering.
AppBannerSettingsHelper - Tracks history of banner events (shown, ignored, dismissed) to enforce rate limiting.

3. Identifiers

Web apps use specific identifiers to track installations and partition data.

See Web App Identifiers for details on Manifest ID, App ID, and platform-specific identifiers.

Deep Dives (Android-specific)

Documentation Guidelines

Following the model of Desktop Web Apps README:

Markdown documentation (in docs/) should focus on high-level architecture, cross-class interactions, and concepts.
Class-level documentation (in header files) should document the responsibilities of individual classes and their APIs.

Web Apps Shared Component (components/webapps)