[AI Chat]: Add TabInformer so the front end can be aware of open tabs

[fallaciousreasoning]

Resolves brave/brave-browser#43221

Meta Issue (with more detail): brave/brave-browser#42711

This PR is the first part of a series for adding support for associating a tab with a full page chat. It implements a mojo service for getting information about the currently active tabs/windows. This PR does not make any frontend changes

Submitter Checklist:

• I confirm that no security/privacy review is needed and no other type of reviews are needed, or that I have requested them
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

N/A - no user visible changes from this PR

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[petemill]

nice work - much nicer than how I achieved similar!

[petemill]

moved from ai_chat_service.cc's kAllowedSchemes so shouldn't need security review

[petemill]

😉

[github-actions]

[puLL-Merge] - brave/brave-core@27187

Description

This PR introduces a new feature for the AI Chat functionality in Brave browser. It adds a TabInformer class that tracks and provides information about open tabs and windows. This information can be used to associate tabs with AI chat conversations, allowing for more context-aware interactions.

Changes

Changes

1. browser/brave_content_browser_client.cc:

   • Added binding for the new TabInformer interface.

2. browser/ui/ai_chat/tab_informer.cc and tab_informer.h:

   • Implemented the new TabInformer class to track and provide information about open tabs and windows.

3. browser/ui/webui/ai_chat/ai_chat_ui.cc and ai_chat_ui.h:

   • Added support for the new TabInformer in the AI Chat UI.

4. components/ai_chat/core/browser/ai_chat_service.cc and ai_chat_service.h:

   • Added a new method AssociateContent to associate tab content with a conversation.

5. components/ai_chat/core/common/mojom/ai_chat.mojom:

   • Updated the SiteInfo struct to include a content_id field.
   • Added a new AssociateTab method to the AIChatUIHandler interface.

6. components/ai_chat/core/common/mojom/tab_informer.mojom:

   • Added a new mojom file defining the TabInformer and TabListener interfaces.

7. components/ai_chat/resources/page/api/index.ts:

   • Updated the TypeScript API to handle tab information and changes.

8. Various test files:

   • Added and updated tests to cover the new functionality.

sequenceDiagram
    participant UI as AI Chat UI
    participant TabInformer
    participant AIChatService
    participant ConversationHandler

    UI->>TabInformer: AddListener
    TabInformer-->>UI: TabsChanged (initial state)
    UI->>AIChatService: AssociateContent
    AIChatService->>ConversationHandler: SetAssociatedContentDelegate
    TabInformer-->>UI: TabsChanged (on tab updates)
    UI->>AIChatService: AssociateContent (for new/changed tabs)

Loading