don't pretend to support dbus on windows in dbus_export.h

dbus/dbus_export.h

Index: dbus/dbus_export.h
diff --git a/dbus/dbus_export.h b/dbus/dbus_export.h
index 0eda41a26fb61e58ea4007088ef589be7c2ef2ae..7c96d1738f6ce12d7deb69c14d909e4054c592d5 100644
--- a/dbus/dbus_export.h
+++ b/dbus/dbus_export.h
@@ -10,16 +10,11 @@
 // NOTE: We haven't used DBUS_EXPORT because it would conflict with the version
 // from /usr/include/dbus-1.0/dbus/dbus-macros.h.
 
-#if defined(COMPONENT_BUILD)
 #if defined(WIN32)
+#error dbus support is not currently expected to work on windows
+#endif  // defined(WIN32)
 
-#if defined(DBUS_IMPLEMENTATION)
-#define CHROME_DBUS_EXPORT __declspec(dllexport)
-#else
-#define CHROME_DBUS_EXPORT __declspec(dllimport)
-#endif  // defined(DBUS_IMPLEMENTATION)
-
-#else  // !defined(WIN32)
+#if defined(COMPONENT_BUILD)
 
 #if defined(DBUS_IMPLEMENTATION)
 #define CHROME_DBUS_EXPORT __attribute__((visibility("default")))
@@ -27,8 +22,6 @@
 #define CHROME_DBUS_EXPORT
 #endif
 
-#endif  // defined(WIN32)
-
 #else  // !defined(COMPONENT_BUILD)
 
 #define CHROME_DBUS_EXPORT