Copy a stable version's .desktop file and modify it to point to your dev build:
  * `cp /usr/share/applications/google-chrome.desktop ~/.local/share/applications/chromium-mybuild-c-release.desktop`
  * `vim ~/.local/share/applications/chromium-mybuild-c-release.desktop`
    * Change first Exec line in desktop entry: (change path to your dev setup)
      * `Exec=/usr/local/google/home/scheib/c/src/out/Release/chrome %U`

Set the default:
  * `xdg-settings set default-web-browser chromium-mybuild-c-release.desktop`

Launch, telling Chrome which config you're using:
  * `CHROME_DESKTOP=chromium-mybuild-c-release.desktop out/Release/chrome`
  * Verify Chrome thinks it is default in `about:settings` page.
    * Press the button to make default if not.

Restore the normal default:
  * `xdg-settings set default-web-browser google-chrome.desktop`


A single line to change the default, run, and restore:
  * `xdg-settings set default-web-browser chromium-mybuild-c-release.desktop && CHROME_DESKTOP=chromium-mybuild-c-release.desktop out/Release/chrome; xdg-settings set default-web-browser google-chrome.desktop && echo Restored default browser.`