Continue with the FreeBSD port - this version builds and links, though...

chrome/common/native_web_keyboard_event.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_NATIVE_WEB_KEYBOARD_EVENT_H_
 #define CHROME_COMMON_NATIVE_WEB_KEYBOARD_EVENT_H_
 
 #include "base/basictypes.h"
 #include "webkit/api/public/WebInputEvent.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_MACOSX)
 #ifdef __OBJC__
 @class NSEvent;
 #else
 class NSEvent;
 #endif  // __OBJC__
-#elif defined(OS_LINUX)
+#elif defined(USE_X11)
 #include <gdk/gdk.h>
 #endif
 
 // Owns a platform specific event; used to pass own and pass event through
 // platform independent code.
 struct NativeWebKeyboardEvent : public WebKit::WebKeyboardEvent {
   NativeWebKeyboardEvent();
 
 #if defined(OS_WIN)
   NativeWebKeyboardEvent(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam);
 #elif defined(OS_MACOSX)
   explicit NativeWebKeyboardEvent(NSEvent *event);
   NativeWebKeyboardEvent(wchar_t character,
                          int state,
                          double time_stamp_seconds);
-#elif defined(OS_LINUX)
+#elif defined(USE_X11)
   explicit NativeWebKeyboardEvent(const GdkEventKey* event);
   NativeWebKeyboardEvent(wchar_t character,
                          int state,
                          double time_stamp_seconds);
 #endif
 
   NativeWebKeyboardEvent(const NativeWebKeyboardEvent& event);
   ~NativeWebKeyboardEvent();
 
   NativeWebKeyboardEvent& operator=(const NativeWebKeyboardEvent& event);
 
 #if defined(OS_WIN)
   MSG os_event;
 #elif defined(OS_MACOSX)
   NSEvent* os_event;
-#elif defined(OS_LINUX)
+#elif defined(USE_X11)
   GdkEventKey* os_event;
 #endif
 };
 
 #endif  // CHROME_COMMON_NATIVE_WEB_KEYBOARD_EVENT_H_