Other good doc page: https://code.facebook.com/posts/393927910787513/stetho-a-new-debugging-platform-for-android/

Felix - feel like taking this on?

v1 would be with no rhino, but certainly there's immense value on adding rhino afterwards as well.

Update:
So far we can hook in Stetho; however, the database inspection feature is not working.
The untested hypothesis is that we need to initialize Stetho with a customized DatabaseFilesProvider that can correctly locate the database files inside chrome.
See DefaultDatabaseFilesProvider and SqliteDatabaseDriver
https://github.com/facebook/stetho/blob/36aa5bd356d9cf5893b9424b06a83dda9ec5e44f/stetho/src/main/java/com/facebook/stetho/inspector/database/DefaultDatabaseFilesProvider.java
https://github.com/facebook/stetho/blob/36aa5bd356d9cf5893b9424b06a83dda9ec5e44f/stetho/src/main/java/com/facebook/stetho/inspector/database/SqliteDatabaseDriver.java

Also, for levelDb support, see https://github.com/facebook/stetho/issues/309

Aside from database inspection, we plan to investigate js rhino & urlconnection
https://github.com/facebook/stetho/tree/36aa5bd356d9cf5893b9424b06a83dda9ec5e44f/stetho-urlconnection
https://github.com/facebook/stetho/tree/36aa5bd356d9cf5893b9424b06a83dda9ec5e44f/stetho-js-rhino

Short summary of progress:
Stetho & Stetho's Rhino module can be integrated into clank's dev build, using build structure similar to LeakCanary https://cs.chromium.org/chromium/src/third_party/leakcanary/BUILD.gn?sq=package:chromium&dr

However, Stetho & Stetho's Rhino module should be not checked into third_party/ due to patent restrictions in its licensing. We need to instruct developers to acquire Stetho, Stetho's Rhino module, and Rhino themselves.

For Mozilla's Rhino to work in our tool chain, we need to specify include_java_resources flag for Rhino's jar, as it contains resources.

Rhino integration works. For example, we can use
org.chromium.chrome.browser.preferences.ChromePreferenceManager.getInstance(null) to update preferences, and changes can be verified. Similar singletons can be found via code search pattern:
getinstance file:java -file:third_party -file:test

Because we cannot check in Stetho and related libs into third_party/, the integration would come at a greater cost. We need to investigate whether Stetho & Rhino is worthy.

One more update on my thoughts on this:
HierarchyViewer exists, and it's likely that Android Studio will make improvements to it.
Stetho's Rhino integration is mainly just the devtools glue. We could probably enable a rhino via telnet bridge fairly easily without the need for stetho if we think this is the main value add.