Remove unused dependencies and add dependencies documentation

[mattleibow]

Summary

Remove 18 unused native dependencies from Skia's DEPS file and add comprehensive dependency documentation.

Changes

Documentation

• New: documentation/dependencies.md - Comprehensive dependency reference including:
  • Security-relevant dependencies (10 total)
  • GPU/graphics dependencies
  • Unused dependencies with reasons for exclusion
  • Platform-specific usage details
  • cgmanifest.json mapping table

Skills

• Update security-audit skill to reference central documentation
• Update native-dependency-update skill to reference central documentation

Submodule (mono/skia#164)

• Comment out 18 unused dependencies in DEPS
• Retain 15 active dependencies

Dependencies Removed

Dependency	Reason
abseil-cpp	Dawn/WebGPU only (disabled)
egl-registry	No BUILD.gn references
highway	libjxl only (disabled)
imgui	Viewer tool only
libavif	skia_use_libavif=false
libgav1	libavif dependency
libgrapheme	skia_use_libgrapheme=false
libjxl	skia_use_libjxl_decode=false
libyuv	libavif dependency
microhttpd	skiaserve tool only
oboe	audioplayer/viewer only
opengl-registry	No BUILD.gn references
spirv-headers	spirv-tools dependency (dev builds)
spirv-tools	is_skia_dev_build only
vello	skia_enable_vello_shaders=false
vulkan-deps	Meta-repo, not directly used
vulkan-tools	Debugging tools only
vulkan-utility-libraries	Debugging only

Dependencies Retained (15)

brotli, d3d12allocator, dng_sdk, expat, freetype, harfbuzz, libjpeg-turbo, libpng, libwebp, piex, spirv-cross, vulkan-headers, vulkanmemoryallocator, wuffs, zlib

Verification

Local builds verified:

• ✅ macOS (arm64)
• ✅ iOS (all architectures)
• ✅ Android (arm64)

Related

• Remove unused dependencies from DEPS skia#164

[github-actions]

Triage Summary

Labels will be applied to indicate the affected components, including dependencies associated with SkiaSharp, Vulkan, and various operating systems (macOS, iOS, and Android), along with documentation.

This issue is not identified as a regression, as it pertains to maintenance tasks rather than a loss of functionality or performance.

Additional remarks:

• The issue mainly focuses on housekeeping tasks such as removing unused dependencies and enhancing documentation, so no labels were deemed necessary for performance, compatibility, or reliability.

Detailed Summary and Actions

Summary of the triage:

• The issue deals with cleaning up unused dependencies and updating documentation, specifically within the Skia project.
• Relevant platforms affected include macOS, iOS, and Android.
• The discussion involves both SkiaSharp and Vulkan functionalities, particularly in the context of local builds and dependencies.
• The proposed actions emphasize the documentation aspect without directly touching on performance or compatibility issues.

Summary of the actions that will be performed:

Action	Item	Description
Apply Label	backend/SkiaSharp	The issue involves removing unused dependencies and updating documentation related to Skia.
Apply Label	backend/Vulkan	The issue discusses Vulkan-related dependencies and their usage within the Skia project.
Apply Label	os/macOS	The issue includes verification of local builds on macOS (arm64).
Apply Label	os/iOS	The issue mentions verification on iOS (all architectures).
Apply Label	os/Android	The issue references verification on Android (arm64).
Apply Label	area/Docs	The issue involves creating comprehensive dependency documentation.

This entire triage process was automated by AI and mistakes may have been made. Please let us know so we can continue to improve.