Make unittests work in component build

src/v8.h

Index: src/v8.h
diff --git a/src/v8.h b/src/v8.h
index a1b18b20d6c05bb62dcc25eab20b07f19a4ae8bc..e49cb0061ca7c2d51623077b04ef8934022499bb 100644
--- a/src/v8.h
+++ b/src/v8.h
@@ -7,6 +7,7 @@
 
 #include "include/v8.h"
 #include "src/allocation.h"
+#include "src/globals.h"
 
 namespace v8 {
 namespace internal {
@@ -25,7 +26,7 @@ class V8 : public AllStatic {
 
   static void InitializePlatform(v8::Platform* platform);
   static void ShutdownPlatform();
-  static v8::Platform* GetCurrentPlatform();
+  V8_EXPORT_PRIVATE static v8::Platform* GetCurrentPlatform();
   // Replaces the current platform with the given platform.
   // Should be used only for testing.
   static void SetPlatformForTesting(v8::Platform* platform);