Add -bootclasspath argument to javac.

build/android/tests/multiple_proguards/src/dummy/DummyActivity.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 dummy;
-
-import android.app.Activity;
-
-/**
- * Dummy activity to build apk.
- *
- * This class is created to ensure that proguard will produce two separate warnings.
- */
-public class DummyActivity extends Activity {
-    private static void doBadThings1() {
-        try {
-            sun.misc.Unsafe.getUnsafe();
-        } catch (Exception e) {
-            throw new Error(e);
-        }
-    }
-
-    private static void doBadThings2() {
-        sun.reflect.Reflection.getCallerClass(2);
-    }
-}