Move V8EXPORT definition to its own file

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 7a71bf10f2abebdd4910fe0bfed60fd7e0357f66..11c5293a4db8a27d9201aa2e41b63bd7d73b3e79 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -30,36 +30,6 @@
 
 #include "v8.h"
 
-#ifdef _WIN32
-// Setup for Windows DLL export/import. See v8.h in this directory for
-// information on how to build/use V8 as a DLL.
-#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
-#error both BUILDING_V8_SHARED and USING_V8_SHARED are set - please check the\
-  build configuration to ensure that at most one of these is set
-#endif
-
-#ifdef BUILDING_V8_SHARED
-#define V8EXPORT __declspec(dllexport)
-#elif USING_V8_SHARED
-#define V8EXPORT __declspec(dllimport)
-#else
-#define V8EXPORT
-#endif
-
-#else  // _WIN32
-
-// Setup for Linux shared library export. See v8.h in this directory for
-// information on how to build/use V8 as shared library.
-#if defined(__GNUC__) && ((__GNUC__ >= 4) || \
-    (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)) && defined(V8_SHARED)
-#define V8EXPORT __attribute__ ((visibility("default")))
-#else
-#define V8EXPORT
-#endif
-
-#endif  // _WIN32
-
-
 /**
  * Profiler support for the V8 JavaScript engine.
  */
@@ -599,7 +569,4 @@ struct HeapStatsUpdate {
 }  // namespace v8
 
 
-#undef V8EXPORT
-
-
 #endif  // V8_V8_PROFILER_H_