99d8cdad66
This change implements flag expiration, with the same goal but a very different method than the previous implementation (https://chromium-review.googlesource.com/c/chromium/src/+/1729449). This change preserves the flag-metadata.json file as the sole authoritative source for flag expiration data. During the build process, a new script (//tools/flags/generate_expired_list.py) generates a data structure from flag-metadata.json listing flags that are expired at or before the current milestone, with their expiration milestones. Logic in //chrome/browser/about_flags.cc and //chrome/browser/unexpire_flags.cc then conditionally hides these flags, depending on the state of the unexpire flags - see //doc/flag_expiry.md for details about those. Specifically, this change: 1) Renames //tools/flags/list-flags.py to list_flags.py to make it importable as a module; 2) Introduces //chrome/browser/expired_flags_list.h, which describes a data structure for representing expired flags; 3) Introduces //tools/flags/generate_expired_list.py, which takes as inputs //chrome/browser/flag-metadata.json and //chrome/VERSION and generates a C++ source file containing a data structure matching that in expired_flags_list.h; 4) Has the //chrome/browser build target depend on the generated file from step 3; 5) Re-introduces an unexpire flag as described in //doc/flag_expiry.md; 6) Adds logic to //chrome/browser/about_flags.cc to conditionally hide expired flags. This means that flag-metadata.json is the sole determinant of whether a flag is currently expired or not. Note that this change expires all flags whose expiration milestones were *M76* or earlier, not M78 (the current mstone); this is because the backlog of flags to expire is currently quite large. In M79, we will expire flags <= M78, then in M80, we will expire flags <= M80; after that, each milestone Mx will expire flags <= Mx. Also note that this change discards the notion of flag expiry depending on usage metrics - i.e., we will now expire *all* flags that expire before the target milestone, not just the N with the lowest usage. The lowest-usage design proved to be extremely manual to implement and very difficult for developers to predict the results of. Bug: 953690 Change-Id: I7389b667d1e032c795c137cafadf0e5e80fb82c1 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1754762 Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org> Reviewed-by: Nico Weber <thakis@chromium.org> Cr-Commit-Position: refs/heads/master@{#690742}
Chromium docs
This directory contains chromium project documentation in Gitiles-flavored Markdown. It is automatically rendered by Gitiles.
If you add new documents, please also add a link to them in the Document Index below.
[TOC]
Creating Documentation
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Document Index
Checking Out and Building
- Linux Build Instructions - Linux
- Mac Build Instructions - MacOS
- Windows Build Instructions - Windows
- Android Build Instructions - Android target (on a Linux host)
- Cast Build Instructions - Cast target (on a Linux host)
- Cast for Android Build Instructions - Cast for Android (on a Linux host)
- Fuchsia Build Instructions - Fuchsia target (on a Linux host)
- iOS Build Instructions - iOS target (on a MacOS host)
- Chrome OS Build Instructions - Chrome OS
- Linux Chromium ARM Recipes - Recipes for building Chromium for ARM on Linux.
- Chrome Component Build - Faster builds using more libraries
- Using the BuildRunner - Scripts that extract build stops from builders and runs them locally on a slave
- Cr User Manual - Manual for
cr, a tool that tries to hide some of the tools used for working on Chromium behind an abstraction layer
Design Docs
- See design/README.md
Integrated Development Environment (IDE) Set Up Guides
- Android Studio - Android Studio for Android builds
- Eclipse for Android - Eclipse for Android
- Eclipse for Linux - Eclipse for other platforms (This guide was written for Linux, but is probably usable on Windows/MacOS as well)
- Qt Creator - Using Qt Creator as an IDE or GUI debugger
- Setting up Visual Studio Code - Visual Studio Code
- EMACS Notes - EMACS commands/styles/tool integrations
- Atom - Atom multi-platform code editor
Git
- Git Cookbook - A collection of git recipes for common tasks
- Git Tips - More git tips
Clang
- Clang Compiler - General information on the clang compiler, used by default on Mac and Linux
- Clang Tool Refactoring - Leveraging clang tools to perform refactorings that are AST-aware
- The Clang Static Analyzer - How to enable static analysis at build time
- Clang Code Coverage Wrapper - Enable Clang code coverage instrumentation for a subset of source files.
- Writing Clang Plugins - Don't write a clang plugin, but if you do, read this
- Updating Clang - Updating the version of Clang used to build
- Using clang-format on Chromium C++ Code - Various ways to invoke clang-format on C++ code
- Clang Tidy - Support for the
clang-tidytool in Chromium - Updating Clang Format Binaries - How up update the clang-format binaries that come with a checkout of Chromium
General Development
- Contributing to Chromium - Reference workflow process for contributing to the Chromium code base.
- Commit Checklist - Streamlined checklist to go through before uploading CLs on Gerrit.
- Code Reviews - Code review requirements and guidelines
- Respectful Code Reviews - A guide for code reviewers
- Respectful Changes - A guide for code authors
- LUCI Migration FAQ - FAQ on Buildbot-to-LUCI builder migration for Chromium
- Tour of Continuous Integration UI - A tour of our the user interface for LUCI, our continuous integration system
- Parsing Test Results - An introduction for how to understand the results emitted by polygerrit and CI builds.
- Closure Compilation - The Closure JavaScript compiler
- Threading and Tasks in Chrome - How to run tasks and handle thread safety in Chrome.
- Callback<> and Bind() - All about Callbacks, Closures, and Bind().
- Views Platform Styling - How views are styled to fit in different native platforms
- Tab Helpers - Using WebContents/WebContentsObserver to add features to browser tabs.
- Adding third_party Libraries - How to get code into third_party/
- Graphical Debugging Aid for Chromium Views - Visualizing view trees during debugging
- Bitmap Pipeline - How bitmaps are moved from the renderer to the screen.
- base::Optional - How to use
base::Optionalin C++ code. - Using the Origin Trials Framework - A framework for conditionally enabling experimental APIs for testing.
ClientTagBasedModelTypeProcessorin Unified Sync and Storage - Notes on the central data structure used in Chrome Sync.- Chrome Sync's Model API - Data models used for syncing information across devices using Chrome Sync.
- Ozone Overview - Ozone is an abstraction layer between the window system and low level input and graphics.
- Optimizing Chrome Web UIs - Notes on making webuis more performant
- Adding a new feature flag in chrome://flags - Quick guide to add a new feature flag to experiment your feature.
- Guidelines for considering branch dates in project planning - What to do (and not to do) around branch dates when scheduling your project work.
- WebUI Explainer - An explanation of C++ and JavaScript infrastructural code for Chrome UIs implemented with web technologies (i.e. chrome:// URLs).
- Watchlists - Use watchlists to get notified of CLs you are interested in.
Testing
- Running and Debugging Web Tests
- Writing Web Tests - Web Tests using
content_shell - Web Test Expectations and Baselines - Setting expected results of web tests.
- Web Tests Tips - Best practices for web tests
- Web Tests with Manual Fallback - Writing tests that simulate manual interventions
- Extending the Web Test Framework
- Fixing Web Test Flakiness - Diagnosing and fixing web test flakiness due to ordering dependencies.
- Running Web Tests using
content_shell- Running web tests by hand. - Web Platform Tests - Shared tests across browser vendors
- Using Crashpad with
content_shell- Capture stack traces on layout test crashes without an attached debugger - Test Descriptions - Unit test targets that can be built, with associated desciptions.
- IPC Fuzzer - Fuzz testing of Chromium IPC interfaces.
- Running Chrome tests with AddressSanitizer (asan) and LeakSanitizer (lsan) - Run Chrome tests with ASAN and LSAN builds to detect addressability issues and memory leaks.
- Code Coverage - Code coverage for Chromium.
- Code Coverage in Gerrit - Per-CL code coverage in Gerrit to assist code reviews.
GPU-related docs
- GPU Pixel Wrangling - Instructions for GPU pixel wrangling (the GPU sheriffing rotation).
- Debugging GPU related code - Hints for debugging GPU- and graphics-related code.
- GPU Testing - Description of Chromium's GPU testing infrastructure.
- GPU Bot Details - In-depth description of how the bots are maintained.
Misc Linux-Specific Docs
- Linux Proxy Config - Network proxy sources on Linux
- Debugging SSL on Linux - Tips on debugging SSL code in Linux
- Linux Cert Managment - Managing X.509 Certificates in Linux
- Tips for Debugging on Linux
- Linux GTK Theme Integration - Having Chrome match the GTK+ theme.
- Browser Plugins on Linux - A collection of links to information on how browser plugins work on Linux
- Linux Crash Dumping - How Breakpad uploads crash reports to Google crash servers.
- Linux Minidump to Core - How to convert a Breakpad-generated minidump files to a core file readable by most debuggersx
- Linux Sandbox IPC - The lower level UPC system used to route requests from the bottom of the call stack up into the browser.
- Linux Dev Build as Default Browser - How to configure a Dev build of Chrome as the default browser in Linux.
- Linux Chromium Packages - Packages of Chromium browser (not Chrome) provided by some Linux distributions.
seccompSandbox Crash Dumping - Notes on crash dumping a process running in a seccomp sandbox.- Linux Password Storage - Keychain integrations between Chromium and Linux.
- Linux Sublime Development - Using Sublime as an IDE for Chromium development on Linux.
- Building and Debugging GTK - Building Chromium against GTK using lower optimization levels and/or more debugging symbols.
- Debugging GTK - Using the GTK Debug packages and related tools.
- Chroot Notes - Setting up a chroot to work around libfreetype differences in some versions of Linux.
- Linux Sandboxing - The Linux multi-process model to isolate browser components with different privileges.
- Zygote Process - How the Linux Zygote process, used to spawn new processes, works.
- Running Web Tests on Linux - Linux-specific instructions for running web tests.
- Linux Sysroot Images - How builds use libraries on Linux
- Linux Hardware Video Decoding - Enabling hardware video decode codepaths on Linux
Misc MacOS-Specific Docs
- Using CCache on Mac - Speed up builds on Mac using ccache with clang/ninja
- Cocoa tips and tricks - A collection of idioms used when writing Cocoa views and controllers
- MacViews Release Plan
Misc Windows-Specific Docs
- Handling cygwin rebaseall failures
- Hacking on ANGLE in Chromium - OpenGL ES 2.0 built on top of DirectX
- Windows Split DLLs - Splitting
chrome.dllinto multiple dlls to work around toolchain limitations on Windows.
Misc Android-Specific Docs
- Google Play Services in Chrome for Android
- Accessing C++ Enums in Java - How to use C++-defined enums in Java code
- Profiling Content Shell on Android -
Setting up profiling for
content_shellon Android - Working Remotely with Android - Building on a remote machine for an Android device connected to your local machine
- Android Test Instructions - Running a build on an Android device or emulator.
- Android Debugging - Tools and tips for how to debug Java and/or C/C++ code running on Android.
- Android Logging - How Chrome's logging API works with
android.util.Logon Android, and usage guidelines. - Chromoting Android Hacking - Viewing the logs and debugging the Chrome Remote Desktop Android client.
- Android Java Static Analysis - Catching Java related issues at compile time with the 'lint' tool.
- Java Code Coverage - Collecting code coverage data with the EMMA tool.
- Android BuildConfig files - What are .build_config files and how they are used.
- Android App Bundles - How to build Android app bundles for Chrome.
- Dynamic Feature Modules (DFMs) - How to create dynamic feature modules.
Misc iOS-Specific Docs
- Continuous Build and Test Infrastructure for Chromium for iOS
- Opening links in Chrome for iOS - How to have your iOS app open links in Chrome.
- User Agent in Chrome for iOS - Notes on User Agent strings using Chrome for iOS.
- Running iOS test suites locally
Misc Chrome-OS-Specific Docs
- Setting up captive portals and other restrictive networks
- Enterprise Enrollment
- Debugging UI in OOBE/login/lock
- Chrome Logging on Chrome OS
Misc WebUI-Specific Docs
- Creating WebUI Interfaces in components/ How to
create a new WebUI component in the
components/directory.
Media
- Audio Focus Handling - How multiple MediaSession audio streams interact
- Autoplay of HTMLMediaElements - How HTMLMediaElements are autoplayed.
- Piranha Plant - Future architecture of MediaStreams
- Video Decode/Encode Accelerator Tests - How to use the accelerated video decoder/encoder test programs.
- Video Decoder Tests - Running the new video decoder tests.
- Video Decoder Performance Tests - Running the new video decoder performance tests.
Accessibility
- Accessibility Overview - Overview of accessibility concerns and approaches in Chromium.
- Accessibility Tests - Where to find accessibility-related tests in the codebase.
- ChromeVox on Chrome OS - Enabling spoken feedback (ChromeVox) on Chrome OS.
- ChromeVox on Desktop Linux - Enabling spoken feedback (ChromeVox) on desktop Linux.
- Offscreen, Invisible and Size - How Chrome defines offscreen, invisible and size in the accessibility tree.
- Text to Speech - Overview of text to speech in Chrome and Chrome OS.
- BRLTTY in Chrome OS - Chrome OS integration with BRLTTY to support refreshable braille displays
- PATTS on Chrome OS - Notes on the PATTS speech sythesis engine used on Chrome OS
- VoiceOver - Using Apple's VoiceOver feature with Chromium on iOS.
Memory
Memory Infrastructure Timeline Profiling (MemoryInfra)
- Overview
- GPU Profiling
- Adding Tracing to a Component
- Enabling Startup Tracing
- Memory Usage in CC
- Memory Benchmarks
- Heap Profiling
Misc
- Useful URLs - A collection of links to various tools and dashboards
- ERC IRC - Using ERC in EMACS to access IRC
- Kiosk Mode - Simulating kiosk mode.
- User Handle Mapping - Names of developers across Chromium/IRC/Google
- Documentation Best Practices
- Documentation Guidelines
- Chromium Browser vs Google Chrome - What's the difference between Chromium Browser and Google Chrome?
- Google Chrome branded builds
- Proxy Auto Config using WPAD - How WPAD servers are used to automatically set proxy settings.
- Installing Chromium OS on VMWare - How to install Chromium OS on VMWare.
- User Data Directory - How the user data and cache directories are determined on all platforms.
Mojo & Services
- Intro to Mojo & Services - Quick introduction to Mojo and services in Chromium, with examples
- Mojo API Reference - Detailed reference documentation for all things Mojo
- The Service Manager & Services - Services system overview, API references, example services
- Service Development Guidelines - Guidelines for service development in the Chromium tree
- Servicifying Chromium Features - General advice for integrating new and existing subsystems into Chromium as services
- Converting Legacy IPC to Mojo - Tips and common patterns for practical IPC conversion work
- Mojo “Style” Guide - Recommendations for best practices from Mojo and IPC reviewers
WebXR
- Running OpenVR Without Headset - Instructions for running OpenVR on Windows without a headset
Probably Obsolete
- TPM Quick Reference - Trusted Platform Module notes.
- System Hardening Features - A list of current and planned Chrome OS security features.
- WebView Policies
- Linux Profiling - How to profile Chromium on Linux
- Linux Graphics Pipeline
- Linux
SUIDSandbox - Sandboxing renderers using a SUID binary on Linux - Linux
SUIDSandbox Development - Development on the above system. - Linux PID Namespace Support
- Vanilla msysgit workflow - A workflow for using mostly vanilla git on Windows.
- Old Chromoting Build Instructions
- Old Options - Pre-Material Design chrome://settings notes.