Add the pointer type of pen to the synthetic WebMousEvent

content/browser/renderer_host/input/synthetic_pen_driver.cc

Index: content/browser/renderer_host/input/synthetic_pen_driver.cc
diff --git a/content/browser/renderer_host/input/synthetic_pen_driver.cc b/content/browser/renderer_host/input/synthetic_pen_driver.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a144b3bf1df9c8c61f4af4114d75c09a2b326180
--- /dev/null
+++ b/content/browser/renderer_host/input/synthetic_pen_driver.cc
@@ -0,0 +1,15 @@
+// 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.
+
+#include "content/browser/renderer_host/input/synthetic_pen_driver.h"
+
+namespace content {
+
+SyntheticPenDriver::SyntheticPenDriver() : SyntheticMouseDriver() {
+  mouse_event_.pointerType = blink::WebPointerProperties::PointerType::Pen;
+}
+
+SyntheticPenDriver::~SyntheticPenDriver() {}
+
+}  // namespace content