[Android] Add an out-of-app instrumentation driver APK. (RELAND)

base/android/java/src/org/chromium/base/ThreadUtils.java

Index: base/android/java/src/org/chromium/base/ThreadUtils.java
diff --git a/base/android/java/src/org/chromium/base/ThreadUtils.java b/base/android/java/src/org/chromium/base/ThreadUtils.java
index 2a8deebfbd5eaeb7c500698178d93f83437c9d14..c0b91721bd45ffe88a6978605ee403c8d8ea10c8 100644
--- a/base/android/java/src/org/chromium/base/ThreadUtils.java
+++ b/base/android/java/src/org/chromium/base/ThreadUtils.java
@@ -176,6 +176,7 @@ public class ThreadUtils {
      * @param task The Runnable to run
      * @param delayMillis The delay in milliseconds until the Runnable will be run
      */
+    @VisibleForTesting
     public static void postOnUiThreadDelayed(Runnable task, long delayMillis) {
         getUiThreadHandler().postDelayed(task, delayMillis);
     }