Add experimental Support for DOM3 KeyboardEvent key value

Source/platform/PlatformKeyboardEvent.h

 /*
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008 Collabora, Ltd.  All rights reserved.
  *
  * 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 28 matching lines @@
     PlatformKeyboardEvent()
         : PlatformEvent(PlatformEvent::KeyDown)
         , m_windowsVirtualKeyCode(0)
         , m_nativeVirtualKeyCode(0)
         , m_autoRepeat(false)
         , m_isKeypad(false)
         , m_isSystemKey(false)
     {
     }
 
-    PlatformKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& keyIdentifier, const String& code, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, Modifiers modifiers, double timestamp)
+    PlatformKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& keyIdentifier, const String& code, const String& key, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, Modifiers modifiers, double timestamp)
         : PlatformEvent(type, modifiers, timestamp)
         , m_text(text)
         , m_unmodifiedText(unmodifiedText)
         , m_keyIdentifier(keyIdentifier)
         , m_code(code)
+        , m_key(key)
         , m_windowsVirtualKeyCode(windowsVirtualKeyCode)
         , m_nativeVirtualKeyCode(nativeVirtualKeyCode)
         , m_autoRepeat(isAutoRepeat)
         , m_isKeypad(isKeypad)
         , m_isSystemKey(isSystemKey)
     {
     }
 
     PLATFORM_EXPORT void disambiguateKeyDownEvent(Type);
 
     // Text as as generated by processing a virtual key code with a keyboard layout
     // (in most cases, just a character code, but the layout can emit several
     // characters in a single keypress event on some platforms).
     // This may bear no resemblance to the ultimately inserted text if an input method
     // processes the input.
     // Will be null for KeyUp and RawKeyDown events.
     String text() const { return m_text; }
 
     // Text that would have been generated by the keyboard if no modifiers were pressed
     // (except for Shift); useful for shortcut (accelerator) key handling.
     // Otherwise, same as text().
     String unmodifiedText() const { return m_unmodifiedText; }
 
     String keyIdentifier() const { return m_keyIdentifier; }
 
     String code() const { return m_code; }
+    String key() const { return m_key; }
 
     // Most compatible Windows virtual key code associated with the event.
     // Zero for Char events.
     int windowsVirtualKeyCode() const { return m_windowsVirtualKeyCode; }
 
     int nativeVirtualKeyCode() const { return m_nativeVirtualKeyCode; }
 
     bool isAutoRepeat() const { return m_autoRepeat; }
     bool isKeypad() const { return m_isKeypad; }
     bool isSystemKey() const { return m_isSystemKey; }
 
     PLATFORM_EXPORT static bool currentCapsLockState();
     PLATFORM_EXPORT static void getCurrentModifierState(bool& shiftKey, bool& ctrlKey, bool& altKey, bool& metaKey);
 
 protected:
     String m_text;
     String m_unmodifiedText;
     String m_keyIdentifier;
     String m_code;
+    String m_key;
     int m_windowsVirtualKeyCode;
     int m_nativeVirtualKeyCode;
     bool m_autoRepeat;
     bool m_isKeypad;
     bool m_isSystemKey;
 };
 
 } // namespace blink
 
 #endif // PlatformKeyboardEvent_h