etiennep-chromium

This commit **enhances the Perfetto UI Recorder** by adding new UI elements to the **Chrome tracing categories tab**, providing more detailed information to users. It introduces the capability to display **category descriptions on hover** and associated **tags as chips** directly next to the category names, improving clarity for tracing options. This **new feature** also unifies the display of "disabled-by-default" categories with normal ones within the same list. The underlying `MultiSelect` widget was extended to support these custom labels and hover details, impacting the `ChromeCategoriesWidget` and `renderOptions` components.

This commit delivers a **bug fix** addressing a **descriptor serialization** issue within the **Chrome extension's tracing controller**. It resolves an incorrect conversion of `Uint8Array` data to a JSON object by `chrome.runtime.Port` during the transmission of tracing configuration. The fix involves **base64 encoding** the `track event descriptor` in `getTrackEventDescriptor` within `ui/src/chrome_extension/chrome_tracing_controller.ts` before sending, and subsequently **base64 decoding** it in the `onExtensionMessage` handler in `ui/src/plugins/dev.perfetto.RecordTraceV2/chrome/chrome_extension_target.ts`. This ensures the accurate and reliable transfer of tracing configuration data, preventing data corruption for the `dev.perfetto.RecordTraceV2` plugin.

This commit **enhances** the **Perfetto Record UI** and its **Chrome extension** integration by switching from simple category strings to the richer `TrackEventDescriptor` objects for tracing configuration. This **feature enhancement** plumbs more detailed information, including tags and descriptions, through the system, affecting how tracing categories are queried and presented in the UI. Modules within `ui/src/chrome_extension/` and `ui/src/plugins/dev.perfetto.RecordTraceV2/` are updated to support this new data structure. While the UI remains functionally equivalent for now, this change lays the groundwork for future improvements in how categories are displayed, particularly in `chrome://traces/recorder`, and includes robust **backward compatibility** fallbacks for older Chrome and extension versions.

This commit **disables several failing unit tests** within the **tracing service's `TraceBufferV2` component**. It performs a **maintenance** action by prepending `DISABLED_` to the names of specific test cases in `src/tracing/service/trace_buffer_v2_unittest.cc`. This change temporarily addresses **UBSAN failures** observed in CI, preventing these problematic tests from executing and unblocking the build process. The scope is limited to these particular unit tests, allowing for further investigation into their underlying issues without blocking continuous integration.

This commit **fixes a build failure** within the `perfetto` project by adding a missing `#include <algorithm>` directive to the **`perfetto/ext/base/circular_queue.h`** utility header. This **maintenance fix** resolves an issue that caused the `perfetto` to **Chromium** roll to break, specifically after a previous commit inadvertently removed an indirect dependency on the `<algorithm>` header. By explicitly including the necessary standard library header, this change ensures the continued successful integration and compilation of `perfetto` within the larger **Chromium** ecosystem.

This commit provides a **bug fix** for the **Perfetto SDK's tracing Flow API**, specifically addressing the `FromPointer` methods. It **updates the parameter type** within `FlowImpl` in `include/perfetto/tracing/track_event_args.h` to accept `const void*` instead of `void*`. This change resolves an incompatibility where the original `void*` parameter was incompatible with constant pointers, improving the robustness and correctness of the `Flow::FromPointer` API. This modification is backward-compatible and **should not break existing usage**, as implicit conversion to `const void*` is supported.

This commit introduces a **new capability** to the **Perfetto SDK**, enabling **Flow tracing IDs** to be optionally scoped using an additional string identifier. This enhancement, similar to `NamedTrack` and legacy Chrome tracing, provides more flexible identification for complex tracing scenarios by adding new static methods like `ProcessScoped` to the `FlowImpl` class in `include/perfetto/tracing/track_event_args.h`. Concurrently, it **refactors** the internal implementation of `Flow` and `TerminatingFlow` into a common class, significantly reducing **code duplication** within the **tracing subsystem**. This change improves the **SDK's tracing capabilities** by offering a more robust and familiar mechanism for correlating events across different scopes, particularly beneficial for users migrating from older tracing systems.

This commit performs a significant **refactoring** within the **tracing subsystem** by **combining the implementations of `Flow` and `TerminatingFlow`** into a single templated class, `FlowImpl`. This change primarily affects `include/perfetto/tracing/track_event_args.h`, where `DefaultFlowTraits` and `TerminatingFlowTraits` are introduced to differentiate the behavior of the previously separate flow types. The `include/perfetto/tracing/track.h` header is updated to reflect these new templated structures, ensuring consistency. This internal simplification aims to **improve maintainability** and facilitate easier interface consistency for flow-related tracing mechanisms in future development.

This commit introduces **new API methods** to the **Perfetto SDK's TrackEvent API**, specifically `TrackEvent::IsCategoryEnabledBySession` and `TrackEvent::IsCategoryEnabledByConfig`. These **new features** allow clients to programmatically determine if a given tracing category is enabled by a specific tracing session or configuration. This provides a more direct and explicit way for observers to control their logic, such as managing timers in Chrome, based on category enablement, rather than relying on side-effects of `OnStart`/`OnStop` calls. It enhances the flexibility and control available when integrating `TrackEvent` into complex systems.

This commit **increases the maximum number of tracing writer IDs** (`kMaxWriterID`) from 1023 to 32767 within the **Perfetto tracing core**. This **bug fix** acts as a **temporary workaround** to prevent data corruption that occurred when high-thread workloads, such as Jetstream2, exceeded the previous limit. The change primarily affects `include/perfetto/ext/tracing/core/basic_types.h` and is accompanied by an update to the `WriterIDsAllocation` unit test in `src/tracing/core/shared_memory_arbiter_impl_unittest.cc` to reflect the new capacity. This allows for the collection of actionable data from previously failing scenarios by accommodating a significantly higher number of concurrent tracing writers.

This commit introduces a **new capability** to **subsample thread time** within the **TrackEvent tracing system**, directly addressing the significant performance overhead identified with frequent thread time sampling. It adds a `thread_time_subsampling_ns` option to the `TrackEventConfig` protobuf definition, allowing users to specify a minimum interval between thread time samples. The core logic for this **performance optimization** is implemented in `src/tracing/internal/track_event_internal.cc`, which now conditionally records thread time based on the configured subsampling interval. This change impacts the **tracing configuration** and **event writing logic**, enabling more efficient tracing by reducing data volume and CPU usage for thread time collection. Additionally, a minor **bug fix** in the `trace_processor` ensures `thread_dur` is only set for non-zero deltas during import.

This commit introduces a **new capability** to the **tracing SDK**, allowing clients to provide an optional custom process UUID during initialization. An optional `process_uuid` field has been added to `TracingInitArgs` in `include/perfetto/tracing/tracing.h`, which is then passed to `TrackRegistry::InitializeInstance`. The `TrackRegistry` in `src/tracing/track.cc` now uses this provided UUID if available, otherwise falling back to automatic generation. This enhancement primarily benefits multi-process environments, such as **Chrome**, by enabling a parent process to pre-assign child process UUIDs, thereby facilitating **direct event emission** and reducing communication overhead.

This commit delivers a **bug fix** addressing an "Unreachable error" that could occur within the **`trace_processor`'s track event handling**. Specifically, it resolves an issue in the `InternDescriptorTrackImpl` function, located in `src/trace_processor/importers/proto/track_event_tracker.cc`, by introducing a **missing early return**. This prevents the error from manifesting when **track merging is disabled**, thereby enhancing the **robustness of trace processing** and ensuring the `trace_processor` operates correctly under all configuration settings.

This commit delivers a **bug fix** within the **Perfetto SDK's tracing API**, specifically addressing an issue in the `NamedTrack` class. It **corrects the return type** of the `ThreadScoped` method, ensuring it now properly returns a `NamedTrack` object instead of a generic `Track`. This change, located in `include/perfetto/tracing/track.h`, resolves an inconsistency where the API was not providing the expected type for thread-scoped named tracks, thereby improving type safety and correct functionality for performance tracing.

This commit introduces a **new capability** to specify an integer-based sibling merge key for tracks, addressing privacy concerns associated with using string identifiers in protobufs. It **enhances the tracing API** by modifying the `TrackDescriptor` protobuf definition to include a `sibling_merge_key_int` field via a `oneof` structure, and updates the `NamedTrack` C++ class with an overloaded `set_sibling_merge_key` method and corresponding member. The **trace processor** is updated to correctly tokenize and intern this new integer merge key from incoming `TrackDescriptor` protos. This change provides a more privacy-preserving mechanism for grouping related tracks within the **Perfetto tracing system**.

This commit **enhances the Chromium recorder** within the **Perfetto UI's tracing plugin** by upgrading it to **version 2**, leveraging `org.chromium.trace_metadata2` and a dedicated DISCARD buffer. This **feature improvement** for the `ui/src/plugins/dev.perfetto.RecordTraceV2` module now supports multiple tracing sessions and significantly reduces the risk of data loss during trace collection. As part of this update, deprecated `chromeConfig` fields (except for memory infrastructure traces) and `clientPriority` are removed, streamlining the configuration. The change improves the robustness and flexibility of Chromium trace recording, aligning with M139 stable support.

This commit introduces **new configuration options** for **ETW system providers** within Perfetto's tracing infrastructure. It adds fields for **scheduling and memory provider events** to the `EtwConfig` message, impacting `protos/perfetto/config/etw/etw_config.proto`, `protos/perfetto/config/perfetto_config.proto`, and `protos/perfetto/trace/perfetto_trace.proto`. This **new capability** is a foundational step towards replacing and deprecating legacy kernel flags for ETW configuration, aligning with modern Windows API practices. Ultimately, it enhances Perfetto's ability to precisely configure and capture detailed system-level ETW traces.

This commit introduces a **new capability** to the **Perfetto tracing SDK** by adding `FromPointer` and `ThreadScoped` static methods to the `NamedTrack` class. These additions allow developers to easily create named tracks using raw pointers as identifiers, providing a convenient shorthand similar to the existing `Track::FromPointer` functionality. This simplifies the process of associating tracing events with specific object instances or memory addresses within the **tracing subsystem**. An integration test, `TrackEventPtrNamedTrack`, has been added to ensure the correct behavior of `NamedTrack::FromPointer`.

This commit introduces a **new API** within the **Perfetto SDK's tracing module** to provide granular control over **`NamedTrack` sibling merge behavior**. It adds methods like `disable_sibling_merge()` and `set_sibling_merge_key()` to the `NamedTrack` class, allowing users to prevent automatic merging or define custom merge keys for tracks. The `NamedTrack::Serialize()` method was updated to persist these new properties, ensuring the configuration is maintained across trace serialization. An integration test was also added to verify the correct behavior and serialization of these new sibling merge properties. This **feature addition** empowers developers to better manage and visualize complex tracing data by explicitly defining how related tracks are grouped.

This commit provides a **bug fix** for the **tracing subsystem**, specifically addressing an issue where the 'slow' tag was inadvertently removed from **dynamic categories**. It **reintroduces the 'slow' tag** for dynamic categories that begin with the `disabled-by-default-` prefix, primarily within the `src/tracing/track_event_category_registry.cc` module. This change resolves a **Chrome autoroll breakage** by restoring the expected behavior for these categories, ensuring proper performance profiling and preventing regressions. The fix impacts the `FromDynamicCategory` symbol, ensuring correct tag assignment for these specific dynamic categories.