Convert most of the rest of instrumentation tests in content

base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java

 // Copyright 2016 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.test;
 
 import android.content.Context;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.internal.runner.junit4.AndroidJUnit4ClassRunner;
 import android.support.test.internal.util.AndroidRunnerParams;
@@ skipping 101 matching lines @@
             new RestrictionSkipCheck(InstrumentationRegistry.getTargetContext()),
             new MinAndroidSdkLevelSkipCheck(),
             new DisableIfSkipCheck()
         });
     }
 
     /**
      * Change this static function to add or take out default {@code PreTestHook}s.
      */
     private static List<PreTestHook> defaultPreTestHooks() {
-        return new ArrayList<PreTestHook>();
+        return null;
     }
 
     /**
      * Evaluate whether a FrameworkMethod is ignored based on {@code SkipCheck}s.
      */
     @Override
     protected boolean isIgnored(FrameworkMethod method) {
         return super.isIgnored(method) || shouldSkip(method);
     }
 
@@ skipping 19 matching lines @@
      */
     private boolean shouldSkip(FrameworkMethod method) {
         for (SkipCheck s : mSkipChecks) {
             if (s.shouldSkip(method)) {
                 return true;
             }
         }
         return false;
     }
 }