am 5cb400bd: Keep track of backup state independently for each transport

Merge commit '5cb400bd72726c22f641f334951b35ce2ddcfeef'

* commit '5cb400bd72726c22f641f334951b35ce2ddcfeef':
  Keep track of backup state independently for each transport

core/java/com/android/internal/backup/IBackupTransport.aidl

@@ -40,6 +40,20 @@ interface IBackupTransport {
         - cloud: tear down connection etc
         - adb: close the file
 */
+    /**
+     * Ask the transport where, on local device storage, to keep backup state blobs.
+     * This is per-transport so that mock transports used for testing can coexist with
+     * "live" backup services without interfering with the live bookkeeping.  The
+     * returned string should be a name that is expected to be unambiguous among all
+     * available backup transports; the name of the class implementing the transport
+     * is a good choice.
+     *
+     * @return A unique name, suitable for use as a file or directory name, that the
+     *         Backup Manager could use to disambiguate state files associated with
+     *         different backup transports.
+     */
+    String transportDirName();
+
     /**
      * Verify that this is a suitable time for a backup pass.  This should return zero
      * if a backup is reasonable right now, some positive value otherwise.  This method

core/java/com/android/internal/backup/LocalTransport.java

@@ -30,6 +30,9 @@ public class LocalTransport extends IBackupTransport.Stub {
     private static final String TAG = "LocalTransport";
     private static final boolean DEBUG = true;
 
+    private static final String TRANSPORT_DIR_NAME
+            = "com.android.internal.backup.LocalTransport";
+
     private Context mContext;
     private PackageManager mPackageManager;
     private File mDataDir = new File(Environment.getDownloadCacheDirectory(), "backup");
@@ -43,6 +46,11 @@ public class LocalTransport extends IBackupTransport.Stub {
         mPackageManager = context.getPackageManager();
     }
 
+
+    public String transportDirName() throws RemoteException {
+        return TRANSPORT_DIR_NAME;
+    }
+
     public long requestBackupTime() throws RemoteException {
         // any time is a good time for local backup
         return 0;