private int getOriginatingUid(final ApplicationInfo caller_info) {
		if (isSystemDownloadsProvider(caller_info.uid) || checkPermission(MANAGE_DOCUMENTS, 0, caller_info.uid) == PERMISSION_GRANTED)
			return getIntent().getIntExtra(EXTRA_ORIGINATING_UID, -1);	// The originating uid provided in the intent from trusted source.
		return caller_info.uid;
	}
@param base_pkg the base package name for split APK installation, or null for full installation.
installer/src/main/java/com/oasisfeng/island/installer/AppInstallerActivity.java