Fix two notification update issues on page navigation

chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTestUtils.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTestUtils.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTestUtils.java b/chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTestUtils.java
new file mode 100644
index 0000000000000000000000000000000000000000..143d234453c44556b6f02a88cd2b70ece27e5654
--- /dev/null
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTestUtils.java
@@ -0,0 +1,33 @@
+// Copyright 2017 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.chrome.browser.media.ui;
+
+import android.app.Instrumentation;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content_public.browser.LoadUrlParams;
+
+/**
+ * Helper functions used in notification instrumentation tests.
+ */
+public class NotificationTestUtils {
+    /**
+     * Simulates a same page navigation.
+     * @param instrumentation The Instrumentation object for the test.
+     * @param tab The tab to be navigated.
+     * @param url The original URL. The URL to be navigated to is |url| + "#some-anchor".
+     */
+    public static void simulateSamePageNavigation(
+            Instrumentation instrumentation, final Tab tab, final String url) {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                tab.loadUrl(new LoadUrlParams(url + "#some-anchor"));
+            }
+        });
+        instrumentation.waitForIdleSync();
+    }
+}