These are instructions for building the Android WebView. These instructions are necessary if you wish to run the WebView code as an Android system component (which is useful when working on performance or application compatibility). To run tests and for certain development tasks it is sufficient to use the standalone test shell as described here.
This workflow currently requires a device with Android Lollipop 5.0.0 release, with root access. Follow instructions at https://source.android.com/source/building.html to build and flash the correct AOSP version to your device. For googlers, see internal instructions. Here's the rough flow of building AOSP for Nexus 5.
Follow the instructions here for getting the source and building chromium for android. The only difference is gyp defines and the build target.
There is a one time device set up to remove the existing webview. This is needed because it is not possible to install over the existing apk due to mismatched signing key.
Install the built apk.
This section describes common scenarios where the android_aosp bot (which is supposed to keep this workflow working) might break:
You've added an (in)direct dependency from the android_webview/ to a third_party library. You can hit this by adding deps to something the android_webview depends on (like content/ or net/ or base/, etc..).
android_webview API changes
You modified the android_webview/ "public" Java API. In some rare cases we export content layer types as part of our public API so it's possible to hit this without touching code in the android_webview folder.Also some content/ Java resources and the R.java resource maps count as the "public" API so touching those can break the bot.