Distinguish between keystroke and character events.

ui/events/cocoa/events_mac.mm

 // Copyright 2014 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 "ui/events/event_utils.h"
 
 #include <Cocoa/Cocoa.h>
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 198 matching lines @@
 }
 
 const char* CodeFromNative(const base::NativeEvent& native_event) {
   return CodeFromNSEvent(native_event);
 }
 
 uint32 PlatformKeycodeFromNative(const base::NativeEvent& native_event) {
   return native_event.keyCode;
 }
 
+bool IsCharFromNative(const base::NativeEvent& native_event) {
+  return false;
+}
+
 }  // namespace ui