Expose resources in Robolectric/JUnit tests.

testing/android/junit/java/src/org/chromium/testing/local/LocalRobolectricTestRunner.java

 // Copyright 2015 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.testing.local;
 
 import org.junit.runners.model.InitializationError;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 import org.robolectric.internal.ManifestFactory;
 
 /**
  * A custom Robolectric Junit4 Test Runner with Chromium specific settings.
  */
 public class LocalRobolectricTestRunner extends RobolectricTestRunner {
     private static final int DEFAULT_SDK = 25;
+    private static final String DEFAULT_PACKAGE_NAME = "org.robolectric.default";
 
     public LocalRobolectricTestRunner(Class<?> testClass) throws InitializationError {
         super(testClass);
     }
 
     @Override
     protected Config buildGlobalConfig() {
-        return new Config.Builder().setSdk(DEFAULT_SDK).build();
+        String packageName =
+                System.getProperty("chromium.robolectric.package.name", DEFAULT_PACKAGE_NAME);
+
+        return new Config.Builder().setSdk(DEFAULT_SDK).setPackageName(packageName).build();
     }
 
     @Override
     protected ManifestFactory getManifestFactory(Config config) {
         return new GNManifestFactory();
     }
 }