Revert r17907 - Make it possible to add more than one piece of embedder data to isolates

src/d8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 74 matching lines @@
 static Handle<Value> Throw(const char* message) {
   return ThrowException(String::New(message));
 }
 
 
 
 class PerIsolateData {
  public:
   explicit PerIsolateData(Isolate* isolate) : isolate_(isolate), realms_(NULL) {
     HandleScope scope(isolate);
-    isolate->SetData(0, this);
+    isolate->SetData(this);
   }
 
   ~PerIsolateData() {
-    isolate_->SetData(0, NULL);  // Not really needed, just to be sure...
+    isolate_->SetData(NULL);  // Not really needed, just to be sure...
   }
 
   inline static PerIsolateData* Get(Isolate* isolate) {
-    return reinterpret_cast<PerIsolateData*>(isolate->GetData(0));
+    return reinterpret_cast<PerIsolateData*>(isolate->GetData());
   }
 
   class RealmScope {
    public:
     explicit RealmScope(PerIsolateData* data);
     ~RealmScope();
    private:
     PerIsolateData* data_;
   };
 
@@ skipping 1673 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif