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.

Creating Documentation

Markdown documents must follow the style guide.

Preview local changes using md_browser:

# in chromium checkout
./tools/md_browser/md_browser.py

This is only an estimate. The gitiles view may differ.

Review changes online with gerrit's links to gitiles:

Upload a patch to gerrit, or receive a review request. e.g. https://chromium-review.googlesource.com/c/572236
View a specific .md file. e.g. https://chromium-review.googlesource.com/c/572236/2/docs/README.md
Click on gitiles link at top of page.

This gitiles view is the authoritative view, exactly the same as will be used when committed.

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-tidy tool in Chromium
Updating Clang Format Binaries - How up update the clang-format binaries that come with a checkout of Chromium

General Development

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::Optional in C++ code.
Using the Origin Trials Framework - A framework for conditionally enabling experimental APIs for testing.
ClientTagBasedModelTypeProcessor in 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.

Testing

Running and Debugging Layout Tests
Writing Layout Tests - Layout Tests using content_shell
Layout Test Expectations and Baselines - Setting expected results of layout tests.
Layout Tests Tips - Best practices for Layout Tests
Layout Tests with Manual Fallback - Writing tests that simulate manual interventions
Extending the Layout Test Framework
Fixing Layout Test Flakiness - Diagnosing and fixing layout test flakiness due to ordering dependencies.
Running Layout Tests using content_shell - Running layout tests by hand.
Web Platform Tests - Shared tests across browser vendors
Using Breakpad 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.

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.
Gtk vs ViewsGtk - Notes on when to use Gtk vs ViewsGtk
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.
seccomp Sandbox 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 Layout Tests on Linux - Linux-specific instructions for running layout 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
Retrieveing Code Analysis Warnings - How to retrieve and summarize the warnings generated by Microsoft VC++'s /analyze compile option.
Windows Split DLLs - Splitting chrome.dll into 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_shell on 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.Log on 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.

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

Chrome Logging on Chrome OS

Media

Audio Focus Handling - How multiple MediaSession audio streams interact
Autoplay of HTMLMediaElements - How HTMLMediaElements are autoplayed.
Piranha Plant - Future architecture of MediaStreams

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 Overview

Memory Infrastructure Timeline Profiling (MemoryInfra)

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?
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 - IPC mechanism used by services.

Probably Obsolete

TPM Quick Reference - Trusted Platform Module notes.
System Hardening Features - A list of current and planned Chrome OS security features.
Browser View Resizer - Design doc for making browser window resizing easier on Windows.
WebView Policies
Linux Profiling - How to profile Chromium on Linux
Linux Graphics Pipeline
Linux SUID Sandbox - Sandboxing renderers using a SUID binary on Linux
Linux SUID Sandbox 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.