Stop leaking the TracingController's BroadcastReciever

sky/shell/android/org/domokit/sky/shell/SkyActivity.java

Index: sky/shell/android/org/domokit/sky/shell/SkyActivity.java
diff --git a/sky/shell/android/org/domokit/sky/shell/SkyActivity.java b/sky/shell/android/org/domokit/sky/shell/SkyActivity.java
index 101c282665a69eac5f649a47fee7c7af9ad19e23..47480222d631d8d1010aa41565d32158ee3ef8fc 100644
--- a/sky/shell/android/org/domokit/sky/shell/SkyActivity.java
+++ b/sky/shell/android/org/domokit/sky/shell/SkyActivity.java
@@ -38,6 +38,16 @@ public class SkyActivity extends Activity {
         mTracingController = new TracingController(this);
     }
 
+    /**
+     * @see android.app.Activity#onStop()
+     */
+    @Override
+    protected void onStop() {
+        // Do we need to shut down Sky too?
+        mTracingController.stop();
+        super.onStop();
+    }
+
     public void loadUrl(String url) {
         mView.loadUrl(url);
     }