How to build Chromium to hack on DevTools

readme.md

A Chromium Compiling Setup for DevTools Hackers

Instructions:

1. Set the args.gn as your gn build configuration

• Probably best to run gn args out/Default and copy/paste what you want to use, then save.

1. source chromium.sh
2. git pull && depsbcr

That's it. You can also run the various components of the bash script seperately and together.

• deps: run gclient sync to synchronize all the "submodule" dependencies
• hooks run gclient hooks, which is otherwise automaticaly run after deps.
• gom: initialize goma
• b: build/compile chrome
• cr: run the built chrome binary

I often do this sequence: git pull && deps && bcr followed by hacking followed by bcr, bcr, bcr. However if you're hacking on DevTools, you often don't need to recompile.

Devtools Debugging

In this config, we've included the debug_devtools = true build setting.

• That allows editing *.js and *.css in your working directory and picking up those changes on devtools re-open. (or alt-r). So, after compiling once, you can make JS & CSS edits without recompiling.
• Also, You will also have "Inspect Element" on the devtools itself for self-debugging.

More

Please read this doc: Chrome DevTools Contribution Guide

Protips:

• Avoid committing to master: run this in src/
  • curl -fL https://gist.githubusercontent.com/stefansundin/9059706/raw/install-pre-commit.sh | sh

args.gn

# Build arguments for the gn build
# You can set these with `gn args out/Default`
#   ( and they're stored in src/out/Default/args.gn )
# See "gn args out/Default --list" for available build arguments

# component build, because people love it
is_component_build = true

# release build, because its faster
is_debug = false

# hardlink'ed devtools frontend. oh yes
debug_devtools = true

# no thx
enable_nacl = false

# This is default for Release builds, but forced regardless
dcheck_always_on = false

# goma only if you're a googler
use_goma = true

chromium.sh

# usage:
# after `git pull`, a full build is now `depsbcr`
# and after changes.. a `bcr` will recompile and relaunch chrome.

function deps () {
    env GYP_DEFINES=disable_nacl=1 gclient sync
}

function hooks () {
    env GYP_DEFINES=disable_nacl=1 gclient runhooks
}

function b () {
    local dir=$(git rev-parse --show-cdup)/out/Default
    # autoninja will automatically determine your -j number based on CPU cores
    local cmd="autoninja -C \"$dir\" chrome" 
    echo "  > $cmd"
    eval "$cmd"
    if [ $? -eq 0 ]; then
        printf "\n✅ Chrome build complete!\n"
        
    fi
}

# you can also add any extra args: `cr --user-data-dir=/tmp/lol123"
function cr () {
    local dir=$(git rev-parse --show-cdup)/out/Default
    local cmd="./$dir/Chromium.app/Contents/MacOS/Chromium $argv"
    echo "  > $cmd"
    eval "$cmd"
}


function gom () {
    # these probably dont make sense for everyone.
    export GOMAMAILTO=/dev/null
    export GOMA_OAUTH2_CONFIG_FILE=$HOME/.goma_oauth2_config
    export GOMA_ENABLE_REMOTE_LINK=yes

    ~/goma/goma_ctl.py ensure_start
}

function bcr () {
    if b; then
        cr
    fi
}


function depsb () {
    if deps; then
        gom
        b
    fi
}

function depsbcr () {
    if deps; then
        gom
        bcr
    fi
}

function hooksbcr () {
    if hooks; then
        gom
        bcr
    fi
}