Enable the -Wundef warning for clang
NOPRESUBMIT=true
BUG=webrtc:6398
Review-Url: https://codereview.webrtc.org/2358993004
Cr-Commit-Position: refs/heads/master@{#14425}
diff --git a/webrtc/common_types.h b/webrtc/common_types.h
index b8c0df4..b1842ef 100644
--- a/webrtc/common_types.h
+++ b/webrtc/common_types.h
@@ -27,9 +27,9 @@
#pragma warning(disable : 4351)
#endif
-#ifdef WEBRTC_EXPORT
+#if defined(WEBRTC_EXPORT)
#define WEBRTC_DLLEXPORT _declspec(dllexport)
-#elif WEBRTC_DLL
+#elif defined(WEBRTC_DLL)
#define WEBRTC_DLLEXPORT _declspec(dllimport)
#else
#define WEBRTC_DLLEXPORT
