Convert most of the rest of instrumentation tests in content

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

Index: base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java
diff --git a/base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java b/base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java
index 57bed8fa558757677c595eb2a62585a78828f6ec..465c23a5d17afdb653cf9646d67813a4dd00d5c3 100644
--- a/base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java
+++ b/base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java
@@ -119,7 +119,7 @@ public class BaseJUnit4ClassRunner extends AndroidJUnit4ClassRunner {
      * Change this static function to add or take out default {@code PreTestHook}s.
      */
     private static List<PreTestHook> defaultPreTestHooks() {
-        return new ArrayList<PreTestHook>();
+        return null;
     }
 
     /**