[Mac] Pressing unsupported key should not generate keyevents

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 #include <stdint.h>
@@ skipping 2094 matching lines @@
   // http://crbug.com/383558.
   if (EventIsReservedBySystem(theEvent))
     return;
 
   DCHECK([theEvent type] != NSKeyDown ||
          !equiv == !([theEvent modifierFlags] & NSCommandKeyMask));
 
   if ([theEvent type] == NSFlagsChanged) {
     // Ignore NSFlagsChanged events from the NumLock and Fn keys as
     // Safari does in -[WebHTMLView flagsChanged:] (of "WebHTMLView.mm").
+    // Also ignore unsupported |keyCode| (255) generated by Convert, NonConvert
+    // and KanaMode from JIS PC keyboard.
     int keyCode = [theEvent keyCode];
-    if (!keyCode || keyCode == 10 || keyCode == 63)
+    if (!keyCode || keyCode == 10 || keyCode == 63 || keyCode == 255)
       return;
   }
 
   // Don't cancel child popups; the key events are probably what's triggering
   // the popup in the first place.
 
   RenderWidgetHostImpl* widgetHost = renderWidgetHostView_->render_widget_host_;
   DCHECK(widgetHost);
 
   NativeWebKeyboardEvent event(theEvent);
@@ skipping 1312 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end