Add GetUsbKeyCode dev interface for Pepper key events

ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h

Index: ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h
diff --git a/ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h b/ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h
index c3cacc046a5822cb1d6c06e242e68a2a64ca154e..b00f28ad83178602b59c48655f9e9f6baa86f119 100644
--- a/ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h
+++ b/ppapi/native_client/src/shared/ppapi_proxy/input_event_data.h
@@ -32,6 +32,10 @@ struct InputEventData {
   PP_Bool wheel_scroll_by_page;
 
   uint32_t key_code;
+  uint32_t usb_scan_code;
+
+  // Required for consistent 64-bit alignment on all platforms.
+  uint32_t unused_padding;
 };
 // Make sure that the size is consistent across platforms, so the alignment is
 // consistent. Note the fields above are carefully ordered to make sure it is
@@ -39,7 +43,7 @@ struct InputEventData {
 // and alignment. TODO(dmichael): This is only required because we don't pickle
 // the type. As a short-cut, we memcpy it instead. It would be cleaner to
 // pickle this struct.
-PP_COMPILE_ASSERT_SIZE_IN_BYTES(InputEventData, 64);
+PP_COMPILE_ASSERT_SIZE_IN_BYTES(InputEventData, 72);
 
 }  // namespace ppapi_proxy