Add experimental Support for DOM3 KeyboardEvent key value

Source/core/events/KeyboardEvent.cpp

Index: Source/core/events/KeyboardEvent.cpp
diff --git a/Source/core/events/KeyboardEvent.cpp b/Source/core/events/KeyboardEvent.cpp
index f55295d0fad1d969af99a231a2b3945d502740ab..8c303607b80054d958b4933adfb949b22b2ea97a 100644
--- a/Source/core/events/KeyboardEvent.cpp
+++ b/Source/core/events/KeyboardEvent.cpp
@@ -97,6 +97,7 @@ KeyboardEvent::KeyboardEvent(const PlatformKeyboardEvent& key, AbstractView* vie
     , m_keyEvent(adoptPtr(new PlatformKeyboardEvent(key)))
     , m_keyIdentifier(key.keyIdentifier())
     , m_code(key.code())
+    , m_key(key.key())
     , m_location(keyLocationCode(key))
     , m_isAutoRepeat(key.isAutoRepeat())

[Wez, 2015/03/04 23:00:25]

Not specific to this CL but perhaps rbyers@ can comment - can we use constructor
delegation now in Blink, to simplify these?

 {
@@ -112,10 +113,11 @@ KeyboardEvent::KeyboardEvent(const AtomicString& eventType, const KeyboardEventI
 }
 
 KeyboardEvent::KeyboardEvent(const AtomicString& eventType, bool canBubble, bool cancelable, AbstractView *view,
-    const String& keyIdentifier, const String& code, unsigned location, bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
+    const String& keyIdentifier, const String& code, const String& key, unsigned location, bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
     : UIEventWithKeyState(eventType, canBubble, cancelable, view, 0, ctrlKey, altKey, shiftKey, metaKey)
     , m_keyIdentifier(keyIdentifier)
     , m_code(code)
+    , m_key(key)
     , m_location(location)
     , m_isAutoRepeat(false)
 {