Question: I need to inspect javascript execution (webview widget) in an android application,
 while debugging; through SDK & usb cable and/or http/websockets;
 from destop computer (e.g. chrome running on desktop).

Webkit's sources includes DebuggerServer implementation
 ( platform\_external\_webkit\Source\WebKit\android\wds\DebugServer.cpp )
 accessible at cpp level, and bound if flag WDS is enabled (at build time?)

Source\WebKit\android\jni\WebCoreFrameBridge.cpp:#if ENABLE(WDS)
Source\WebKit\android\jni\WebCoreFrameBridge.cpp: WDS::server()->addFrame(frame);

The default port for server is 9999

The sources show that all is implemented (at Cpp level) to enable the feature,
 but I have not found any reference searching the web for experiences
 using live debugging at javascript level in adroid devices automating
 webkit's inspector interface.

1.- Are the feature present, in binary form, executing in actual android devices?
 (has adroid's distribution of webkit been built without WDS flag enabled? :-( )

2.- Can the remote debug feature be enabled/used from javascript or application
 (at java level) e.g. at startup of app?

3.- In case it is possible to enable the webkit inspector/debugger feature,
 how to make it possible to interact from remote application ? (e.g. from
 another javascript app using websockets, or chrome on desktop computers).

Some paragraphs explaining the mechanics like
 <https://developers.google.com/chrome-developer-tools/docs/remote-debugging#remote>
 would be nice!

thanks in advance for any information, or references about this topic.
I consider important to enable remote debugging (in the device) at
 javascript level to make it possible modern development of HTML5
 applications and happy debugging experience.

cheers,
Ale.

Answer: 
You can do remote debugging targeting the Android Browser with the [weinre](http://people.apache.org/~pmuellr/weinre/docs/latest/) project. Or use [Chrome remote debugging](https://developers.google.com/chrome-developer-tools/docs/remote-debugging) with the Chrome for Android browser. As far as I know, you can't target a WebView directly, but targeting the Android Browser should get you close.
It cannot be done, because the debugger backend code is not there. The source code you are referencing to is a copy of webkit source in android, but it is not compiled into android release bits.