Add GetUsbKeyCode dev interface for Pepper key events

ppapi/cpp/input_event.cc

Index: ppapi/cpp/input_event.cc
diff --git a/ppapi/cpp/input_event.cc b/ppapi/cpp/input_event.cc
index 632b1eccd93652f9f15e227e28bb9fdbf342756c..64f546afff068356d9bfed3ff58e27729da19aaa 100644
--- a/ppapi/cpp/input_event.cc
+++ b/ppapi/cpp/input_event.cc
@@ -195,13 +195,14 @@ KeyboardInputEvent::KeyboardInputEvent(Instance* instance,
                                        PP_TimeTicks time_stamp,
                                        uint32_t modifiers,
                                        uint32_t key_code,
+                                       uint32_t usb_scan_code,
                                        const Var& character_text) {
   // Type check the input event before setting it.
   if (!has_interface<PPB_KeyboardInputEvent>())
     return;
   PassRefFromConstructor(get_interface<PPB_KeyboardInputEvent>()->Create(
       instance->pp_instance(), type, time_stamp, modifiers, key_code,
-      character_text.pp_var()));
+      usb_scan_code, character_text.pp_var()));
 }
 
 uint32_t KeyboardInputEvent::GetKeyCode() const {
@@ -210,6 +211,13 @@ uint32_t KeyboardInputEvent::GetKeyCode() const {
   return get_interface<PPB_KeyboardInputEvent>()->GetKeyCode(pp_resource());
 }
 
+uint32_t KeyboardInputEvent::GetUsbScanCode_Dev() const {
+  if (!has_interface<PPB_KeyboardInputEvent>())
+    return 0;
+  return get_interface<PPB_KeyboardInputEvent>()->GetUsbScanCode_Dev(
+      pp_resource());
+}
+
 Var KeyboardInputEvent::GetCharacterText() const {
   if (!has_interface<PPB_KeyboardInputEvent>())
     return Var();