Stop leaking the TracingController's BroadcastReciever

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

Index: sky/shell/android/org/domokit/sky/shell/TracingController.java
diff --git a/sky/shell/android/org/domokit/sky/shell/TracingController.java b/sky/shell/android/org/domokit/sky/shell/TracingController.java
index 716e0c007d833cdd46b65c79537436af446a9d53..b373747f6dc9fa03aab5833941a640c3000009c8 100644
--- a/sky/shell/android/org/domokit/sky/shell/TracingController.java
+++ b/sky/shell/android/org/domokit/sky/shell/TracingController.java
@@ -8,17 +8,16 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.os.Environment;
 import android.util.Log;
 
+import org.chromium.base.JNINamespace;
+
 import java.io.File;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Locale;
 import java.util.TimeZone;
 
-import org.chromium.base.JNINamespace;
-
 /**
  * A controller for the tracing system.
  */
@@ -40,6 +39,10 @@ class TracingController {
         mContext.registerReceiver(mBroadcastReceiver, mIntentFilter);
     }
 
+    public void stop() {
+        mContext.unregisterReceiver(mBroadcastReceiver);
+    }
+
     private String generateTracingFilePath() {
         SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HHmmss", Locale.US);
         formatter.setTimeZone(TimeZone.getTimeZone("UTC"));