How access the Google Play Account IDs on Android?

I want to access the Google Play account IDs (Email IDs) that are associated with that android phone through code in Unity. Something I don't think unity can do by default using it's API, but I wish I am wrong.

Getting Google play information about accounts associated with a device is possible. There is an app that does that : https://play.google.com/store/apps/details?id=com.redphx.deviceid&hl=en

Here's my understanding of the issue so far - There is a framework available at https://github.com/android/platform_frameworks_opt_com.google.android/ that allows you to access that information. In Eclipse ADT - here's the Java code that we need to add to get the information:

Call the method :-

 com.google.android.googlelogin.GoogleLoginServiceHelper.getAccount
 (Activity activity, int requestCode, boolean requireGoogle);

Add code :-

 protected void onActivityResult(int requestCode, int resultCode, 
     Intent data) { 
             super.onActivityResult(requestCode, resultCode, data); 
             if(requestCode == 123){ 
                 System.out.println(resultCode); 
                 String key = "accounts"; 
                 System.out.println(key + ":" + 
     Arrays.toString(data.getExtras().getStringArray(key))); 
                 String accounts[] = data.getExtras().getStringArray(key); 
                 if(accounts != null){ 
                    int i = 0; 
                    for(String ac : accounts){  //each account is the full 
     email address registered with this device 
                         System.out.println("ac " + i + "=" + ac); 
                          i++; 
                    } 
                 } 
        } 

So, I guess my question is - how can I load up that framework (.jar) into my unity project and run the code?

Or : The other method to do something similar in Eclipse would be to use:

 Pattern emailPattern = Patterns.EMAIL_ADDRESS; // API level 8+
 Account[] accounts = AccountManager.get(context).getAccounts();
 for (Account account : accounts) {
     if (emailPattern.matcher(account.name).matches()) {
         String possibleEmail = account.name;
         ...
     }
 }

Thanks in advance! - Ashwin