title: Memory leak in the empty Activity
body: <p>I recently decided to use <a href="https://github.com/square/leakcanary" rel="nofollow">leakcanary</a> in my projects, So I created a project with an empty <code>Activity</code> just for test, When I run the app (just after project creation with no logic code or views) I got memory leak log from this library:</p>
  
  <pre><code>07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * com.example.leaktest.MainActivity has leaked:
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * GC ROOT static android.app.ActivityThread.sCurrentActivityThread
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * references android.app.ActivityThread.mActivities
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * references android.util.ArrayMap.mArray
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * references array java.lang.Object[].[1]
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * references android.app.ActivityThread$ActivityClientRecord.activity
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * leaks com.example.leaktest.MainActivity instance
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * Retaining: 1.7KB.
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * Reference Key: 9180226a-8a65-4c94-9d12-4562a6d88157
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * Device: Genymotion generic genymotion_vbox86tp_5.1_150409_105318 vbox86tp
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * Android Version: 5.1 API: 22 LeakCanary: 1.4-beta2 3799172
  07-20 04:32:36.742 2967-4915/com.example.leaktest D/LeakCanary: * Durations: watch=5808ms, gc=158ms, heap dump=1953ms, analysis=15795ms
  </code></pre>
  
  <p><strong>App</strong> class:</p>
  
  <pre><code>public class App extends Application {
      @Override
      public void onCreate() {
          super.onCreate();
          refWatcher = LeakCanary.install(this);
      }
  
      public static RefWatcher getRefWatcher(Context context) {
          App application = (App) context.getApplicationContext();
          return application.refWatcher;
      }
  
      private RefWatcher refWatcher;
  }
  </code></pre>
  
  <p><strong>MainActivity</strong> class:</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          App.getRefWatcher(this).watch(this);
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
      }
  }
  </code></pre>
  
  <p>I have no idea why this is happening, I will appreciate if someone explain it to me.</p>