Add experimental Support for DOM3 KeyboardEvent key value

public/web/WebInputEvent.h

Index: public/web/WebInputEvent.h
diff --git a/public/web/WebInputEvent.h b/public/web/WebInputEvent.h
index bbded2e16062e58ed65eea055c3a49e31141a977..85a576a3a95b8b182cfec4a7702f2766a79de9bc 100644
--- a/public/web/WebInputEvent.h
+++ b/public/web/WebInputEvent.h
@@ -256,6 +256,10 @@ public:
     // code enum are defined in ui/events/keycodes/dom4/keycode_converter_data.h.
     int domCode;
 
+    // The DOM key enum of the key pressed as passed by the embedder. DOM

[Wez, 2015/05/06 01:32:13]

Suggest "Embedder-specific value identifying the DOM |key| for the event.

+    // key enum are defined in ui/events/keycodes/dom3/dom_key_data.h

[Wez, 2015/05/06 01:32:13]

The path referred to is in Chromium, whereas this is in Blink code, so this (and
the comment on domCode) should be specific that these are Chromium paths, not
Blink.

+    int domKey;
+
     // This identifies whether this event was tagged by the system as being
     // a "system key" event (see
     // http://msdn.microsoft.com/en-us/library/ms646286(VS.85).aspx for