Add GetUsbKeyCode dev interface for Pepper key events

ppapi/proxy/resource_creation_proxy.cc

Index: ppapi/proxy/resource_creation_proxy.cc
diff --git a/ppapi/proxy/resource_creation_proxy.cc b/ppapi/proxy/resource_creation_proxy.cc
index c77e3c62590fae76b8e467c5e143783d74229982..97ba5ada4514d614d3127f78acd9d9d8d06c9c61 100644
--- a/ppapi/proxy/resource_creation_proxy.cc
+++ b/ppapi/proxy/resource_creation_proxy.cc
@@ -187,6 +187,7 @@ PP_Resource ResourceCreationProxy::CreateKeyboardInputEvent(
     PP_TimeTicks time_stamp,
     uint32_t modifiers,
     uint32_t key_code,
+    uint32_t usb_scan_code,
     struct PP_Var character_text) {
   if (type != PP_INPUTEVENT_TYPE_RAWKEYDOWN &&
       type != PP_INPUTEVENT_TYPE_KEYDOWN &&
@@ -198,6 +199,7 @@ PP_Resource ResourceCreationProxy::CreateKeyboardInputEvent(
   data.event_time_stamp = time_stamp;
   data.event_modifiers = modifiers;
   data.key_code = key_code;
+  data.usb_scan_code = usb_scan_code;
   if (character_text.type == PP_VARTYPE_STRING) {
     StringVar* text_str = StringVar::FromPPVar(character_text);
     if (!text_str)