Added a debug info UI for Blimp

blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java

Index: blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
diff --git a/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java b/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
index d16cbc2703d2178dfc79b1e6ca870fb61721f499..cc7595d3c4fcb0f0c07eee785a4c76a05c41903d 100644
--- a/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
+++ b/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
@@ -49,10 +49,20 @@ public class BlimpClientSession {
         void onDisconnected(String reason);
     }
 
+    public interface NetworkActivityObserver {
+        void onPacketSent(int bytes);
+        void onPacketReceived(int bytes);
+    }
+
     private final String mAssignerUrl;
     private final List<ConnectionObserver> mObservers;
+    private NetworkActivityObserver mDataObserver;
     private long mNativeBlimpClientSessionAndroidPtr;
 
+    public void setDataObserver(NetworkActivityObserver observer) {
+        mDataObserver = observer;
+    }
+
     public BlimpClientSession(String assignerUrl) {
         mAssignerUrl = assignerUrl;
         mObservers = new ArrayList<ConnectionObserver>();
@@ -162,6 +172,16 @@ public class BlimpClientSession {
         return mNativeBlimpClientSessionAndroidPtr;
     }
 
+    @CalledByNative
+    private void onPacketReceived(int bytes) {
+        mDataObserver.onPacketReceived(bytes);
+    }
+
+    @CalledByNative
+    private void onPacketSent(int bytes) {
+        mDataObserver.onPacketSent(bytes);
+    }
+
     private native long nativeInit(String assignerUrl);
     private native void nativeConnect(long nativeBlimpClientSessionAndroid, String token);
     private native void nativeDestroy(long nativeBlimpClientSessionAndroid);