Adding support for DOM3 KeyboardEvents Code in KeyboardEvents

Source/platform/PlatformKeyboardEvent.h

Index: Source/platform/PlatformKeyboardEvent.h
diff --git a/Source/platform/PlatformKeyboardEvent.h b/Source/platform/PlatformKeyboardEvent.h
index a67cc216c84893b9f4c62c5612f8b686a0ea1c10..7634da53550aa95ec12160dc419225e5ee6c3b20 100644
--- a/Source/platform/PlatformKeyboardEvent.h
+++ b/Source/platform/PlatformKeyboardEvent.h
@@ -40,19 +40,21 @@ public:
         : PlatformEvent(PlatformEvent::KeyDown)
         , m_windowsVirtualKeyCode(0)
         , m_nativeVirtualKeyCode(0)
+        , m_usbCode(0)
         , m_autoRepeat(false)
         , m_isKeypad(false)
         , m_isSystemKey(false)
     {
     }
 
-    PlatformKeyboardEvent(Type type, const String& text, const String& unmodifiedText, const String& keyIdentifier, 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, int windowsVirtualKeyCode, int nativeVirtualKeyCode, int usbCode, bool isAutoRepeat, bool isKeypad, bool isSystemKey, Modifiers modifiers, double timestamp)
         : PlatformEvent(type, modifiers, timestamp)
         , m_text(text)
         , m_unmodifiedText(unmodifiedText)
         , m_keyIdentifier(keyIdentifier)
         , m_windowsVirtualKeyCode(windowsVirtualKeyCode)
         , m_nativeVirtualKeyCode(nativeVirtualKeyCode)
+        , m_usbCode(usbCode)
         , m_autoRepeat(isAutoRepeat)
         , m_isKeypad(isKeypad)
         , m_isSystemKey(isSystemKey)
@@ -82,6 +84,8 @@ public:
 
     int nativeVirtualKeyCode() const { return m_nativeVirtualKeyCode; }
 
+    int usbKeyCode() const { return m_usbCode; }
+
     bool isAutoRepeat() const { return m_autoRepeat; }
     bool isKeypad() const { return m_isKeypad; }
     bool isSystemKey() const { return m_isSystemKey; }
@@ -95,6 +99,7 @@ protected:
     String m_keyIdentifier;
     int m_windowsVirtualKeyCode;
     int m_nativeVirtualKeyCode;
+    int m_usbCode;
     bool m_autoRepeat;
     bool m_isKeypad;
     bool m_isSystemKey;