[Android] Incorporate findbugs into android builds.

base/android/javatests/src/org/chromium/base/ObserverListTest.java

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.base;
 
 import android.test.InstrumentationTestCase;
 import android.test.suitebuilder.annotation.SmallTest;
 
 import org.chromium.base.test.util.Feature;
@@ skipping 230 matching lines @@
         observerList.addObserver(b);
 
         assertTrue(observerList.removeObserver(a));
         assertFalse(observerList.removeObserver(a));
         assertFalse(observerList.removeObserver(new Object()));
         assertTrue(observerList.removeObserver(b));
         assertFalse(observerList.removeObserver(null));
 
         // If we remove an object while iterating, it will be replaced by 'null'.
         observerList.addObserver(a);
-        Iterator<Object> iterator = observerList.iterator();
         assertTrue(observerList.removeObserver(a));
         assertFalse(observerList.removeObserver(null));
     }
 
     @SmallTest
     @Feature({"Android-AppBase"})
     public void testSize() {
         ObserverList<Object> observerList = new ObserverList<Object>();
 
         assertEquals(0, observerList.size());
@@ skipping 60 matching lines @@
         assertTrue(observerList.isEmpty());
 
         observerList.removeObserver(a);
         observerList.removeObserver(b);
         observerList.removeObserver(null);
         observerList.removeObserver(new Object());
         assertEquals(0, observerList.size());
         assertTrue(observerList.isEmpty());
     }
 }