Ensuring that we don't start dragging while another drag is in progress.

Change-Id: If3c5a059407efc3ee9a0c9b1b3b7fb942d3a7664

src/com/android/launcher2/DragController.java

@@ -390,6 +390,10 @@ public class DragController {
         return mDragging;
     }
 
+    public boolean isDragging() {
+        return mDragging;
+    }
+
     /**
      * Stop dragging without dropping.
      */