[ads] Profile performance using TRACE events

[tmancey]

Resolves brave/brave-browser#21106

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:

[mkarolin]

chromium_src++

[github-actions]

[puLL-Merge] - brave/brave-core@27181

Here's a description and analysis of the pull request:

Description

This PR adds tracing and performance monitoring capabilities to the Brave Ads component. It introduces trace events at various points in the ad serving pipeline, allowing for better performance analysis and debugging. The changes primarily involve adding trace events, restructuring some callback flows, and improving error handling.

Changes

Changes

1. chromium_src/base/trace_event/builtin_categories.h:

   • Added "brave.ads" to the list of builtin tracing categories.

2. Multiple files:

   • Added #include "base/trace_event/trace_event.h" and #include "base/location.h" to various files.
   • Introduced TRACE_EVENT and TRACE_EVENT_NESTABLE_ASYNC_BEGIN/END macros throughout the codebase to instrument key functions and operations.

3. components/brave_ads/core/internal/database/database.cc:

   • Added tracing to RunDBTransaction, RunDBActions, MaybeRaze, and MaybeVacuum methods.

4. components/brave_ads/core/internal/serving/ directory:

   • Added tracing to various ad serving pipelines (inline content, new tab page, notification).
   • Restructured some callback flows to include trace IDs for better tracking.

5. components/brave_ads/core/internal/targeting/ directory:

   • Added tracing to text classification processor.

6. components/brave_ads/core/internal/user_engagement/ directory:

   • Added tracing to conversion checking and site visit tracking.

7. components/brave_ads/core/public/ads_constants.h:

   • Defined a new constant kTraceEventCategory for "brave.ads".

sequenceDiagram
    participant User
    participant BraveAds
    participant Database
    participant AdServing
    participant Targeting
    participant UserEngagement

    User->>BraveAds: Interact with browser
    BraveAds->>Database: RunDBTransaction
    Note over Database: TRACE_EVENT: Database operations
    Database-->>BraveAds: Transaction result

    BraveAds->>AdServing: Serve ad
    Note over AdServing: TRACE_EVENT: Ad serving pipeline
    AdServing->>Targeting: Get user model
    Note over Targeting: TRACE_EVENT: Text classification
    Targeting-->>AdServing: User model
    AdServing->>UserEngagement: Check for conversions
    Note over UserEngagement: TRACE_EVENT: Conversion checking
    UserEngagement-->>AdServing: Conversion result
    AdServing-->>BraveAds: Served ad

    BraveAds->>User: Display ad

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Possible Issues

• The increased number of trace events may have a small performance impact, especially if tracing is enabled in production builds.
• Some of the restructured callback flows might introduce subtle timing changes in the ad serving pipeline.

Security Hotspots

No significant security issues are apparent in this change. The tracing additions don't expose sensitive information and are primarily for debugging and performance analysis.

This sequence diagram illustrates the high-level flow of the Brave Ads system with the newly added trace events, showing how various components interact and where tracing has been added for performance monitoring.