Fix performance regressions due to lazy initialization.

src/api.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 4152 matching lines @@
         Utils::OpenHandle(this)->SetInternalField(index, *foreign);
   }
   ASSERT_EQ(value, GetPointerFromInternalField(index));
 }
 
 
 // --- E n v i r o n m e n t ---
 
 
 bool v8::V8::Initialize() {
+  i::Isolate::EnsureDefaultIsolate();
   i::Isolate* isolate = i::Isolate::Current();
   if (isolate != NULL && isolate->IsInitialized()) {
     return true;
   }
   return InitializeHelper();
 }
 
 
 void v8::V8::SetEntropySource(EntropySource source) {
   i::V8::SetEntropySource(source);
 }
 
 
 void v8::V8::SetReturnAddressLocationResolver(
       ReturnAddressLocationResolver return_address_resolver) {
   i::V8::SetReturnAddressLocationResolver(return_address_resolver);
 }
 
 
 bool v8::V8::Dispose() {
+  i::Isolate::EnsureDefaultIsolate();
   i::Isolate* isolate = i::Isolate::Current();
   if (!ApiCheck(isolate != NULL && isolate->IsDefaultIsolate(),
                 "v8::V8::Dispose()",
                 "Use v8::Isolate::Dispose() for a non-default isolate.")) {
     return false;
   }
   i::V8::TearDown();
   return true;
 }
 
@@ skipping 2163 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* scope_implementer =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   scope_implementer->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal