Revert "Removed default Isolate."

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #include <cmath>  // For isnan.
 #include "../include/v8-debug.h"
 #include "../include/v8-profiler.h"
@@ skipping 4940 matching lines @@
     ArrayBuffer::Allocator* allocator) {
   if (!Utils::ApiCheck(i::V8::ArrayBufferAllocator() == NULL,
                        "v8::V8::SetArrayBufferAllocator",
                        "ArrayBufferAllocator might only be set once"))
     return;
   i::V8::SetArrayBufferAllocator(allocator);
 }
 
 
 bool v8::V8::Dispose() {
+  i::Isolate* isolate = i::Isolate::Current();
+  if (!Utils::ApiCheck(isolate != NULL && isolate->IsDefaultIsolate(),
+                       "v8::V8::Dispose()",
+                       "Use v8::Isolate::Dispose() for non-default isolate.")) {
+    return false;
+  }
   i::V8::TearDown();
   return true;
 }
 
 
 HeapStatistics::HeapStatistics(): total_heap_size_(0),
                                   total_heap_size_executable_(0),
                                   total_physical_size_(0),
                                   used_heap_size_(0),
                                   heap_size_limit_(0) { }
@@ skipping 2617 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal