Support setting mouse cursor icon in Android N.

content/shell/android/java/src/org/chromium/content_shell/ShellViewAndroidDelegate.java

 // 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.content_shell;
 
+import android.os.Build;
+import android.view.PointerIcon;
 import android.view.ViewGroup;
 
 import org.chromium.ui.base.ViewAndroidDelegate;
 
 /**
  * Implementation of the abstract class {@link ViewAndroidDelegate} for content shell.
  * Extended for testing.
  */
 public class ShellViewAndroidDelegate extends ViewAndroidDelegate {
     private final ViewGroup mContainerView;
+    private Runnable mOnCursorUpdate;
 
     public ShellViewAndroidDelegate(ViewGroup containerView) {
         mContainerView = containerView;
+        mOnCursorUpdate = null;
     }
 
     @Override
     public ViewGroup getContainerView() {
         return mContainerView;
     }
+
+    public void setOnCursorUpdate(Runnable callback) {
+        mOnCursorUpdate = callback;
+    }
+
+    @Override
+    public void updatePointerIcon(PointerIcon icon) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            getContainerView().setPointerIcon(icon);
+            if (mOnCursorUpdate != null) mOnCursorUpdate.run();

[boliu, 2017/05/31 16:30:03]

generally, the pattern is this class holds a CallbackHelper subclass where
notifyCalled takes a parameter that's being checked, in this case PointerIcon.
then test can get it directly from CallbackHelper after waitForCallback.
Example:
https://cs.chromium.org/chromium/src/content/public/test/android/javatests/sr...

[jaebaek, 2017/06/01 06:20:56]

Done.

+        }
+    }
 }