Delete constant declarations from v8_initializer.h that have no definitions

gin/v8_initializer.h

Index: gin/v8_initializer.h
diff --git a/gin/v8_initializer.h b/gin/v8_initializer.h
index 68068c4848b567a696ecaa1c028622df010fe990..0189f594f939322a7b5ec65d2f2612afa5660d4e 100644
--- a/gin/v8_initializer.h
+++ b/gin/v8_initializer.h
@@ -16,10 +16,6 @@ namespace gin {
 
 class GIN_EXPORT V8Initializer {
  public:
-  static const int kV8SnapshotBasePathKey;
-  static const char kNativesFileName[];
-  static const char kSnapshotFileName[];
-
   // This should be called by IsolateHolder::Initialize().
   static void Initialize(gin::IsolateHolder::ScriptMode mode);