Fix false negatives in system key events recognition

Source/web/WebInputEventFactoryMac.mm

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006-2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 805 matching lines @@
     result->movementY = [event deltaY];
 }
 
 bool WebInputEventFactory::isSystemKeyEvent(const WebKeyboardEvent& event)
 {
     // Windows and Linux set |isSystemKey| if alt is down. Blink looks at this
     // flag to decide if it should handle a key or not. E.g. alt-left/right
     // shouldn't be used by Blink to scroll the current page, because we want
     // to get that key back for it to do history navigation. Hence, the
     // corresponding situation on OS X is to set this for cmd key presses.
+
     // cmd-b and and cmd-i are system wide key bindings that OS X doesn't
     // handle for us, so the editor handles them.
-    return event.modifiers & WebInputEvent::MetaKey
-           && event.windowsKeyCode != VK_B
-           && event.windowsKeyCode != VK_I;
+    int modifiers = event.modifiers & WebInputEvent::InputModifiers;
+    if (modifiers == WebInputEvent::MetaKey && event.windowsKeyCode == VK_B)
+        return false;
+    if (modifiers == WebInputEvent::MetaKey && event.windowsKeyCode == VK_I)
+        return false;
+
+    return event.modifiers & WebInputEvent::MetaKey;
 }
 
 WebKeyboardEvent WebInputEventFactory::keyboardEvent(NSEvent* event)
 {
     WebKeyboardEvent result;
 
     result.type =
         isKeyUpEvent(event) ? WebInputEvent::KeyUp : WebInputEvent::RawKeyDown;
 
     result.modifiers = modifiersFromEvent(event);
@@ skipping 354 matching lines @@
         break;
     default:
         ASSERT_NOT_REACHED();
         result.type = WebInputEvent::Undefined;
     }
 
     return result;
 }
 
 } // namespace blink