Hi @xingnan and @kenchris.

Firstly, about the differences of the app: and file: URLs:

The app: URL scheme allows addressing resources within a container (e.g., a .zip file that is the app package). The container is sand-boxed from the the filesystem. The app: URLs behave similarly on all platforms, and there's a spec: http://www.w3.org/2012/sysapps/app-uri/

The file: URLs do not have such restrictions, and allows addressing any files on the filesystem subject to platform-specific limitation. The file: URL format varies from platform to platform, which does not make it useful for cross-platform web apps.

Looking at the patch, the "allow-universal-access-from-file-urls" command line switch sets setAllowFileAccessFromFileURLs to true
http://developer.android.com/reference/android/webkit/WebSettings.html#setAllowFileAccessFromFileURLs(boolean) allowing any JavaScript file loaded from a file: URL to access content from other file: URLs. For example, JS code loaded from a file: URL can XHR files from other file: URLs. Correct?

I'm hearing you have a requirement to allow a JavaScript file loaded from an app: URL (that is, a JS file that resides inside the application package) to load arbitrary files from file: URLs in addition to app: URLs, and you're proposing the "allow-universal-access-from-file-urls" as a mechanism to allow that?

What is the use case behind this requirement? This is powerful capability to be opened up to 3rd party applications. Can the use case be addressed by e.g. using a file picker dialog to let the user to select the files from the filesystem instead?