[d8] Fix LeakSanitizer failures on the bots due to ModuleEmbedderData

src/d8.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 <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 
 #include <algorithm>
@@ skipping 707 matching lines @@
   data_->realm_current_ = 0;
   data_->realm_switch_ = 0;
   data_->realms_ = new Global<Context>[1];
   data_->realms_[0].Reset(data_->isolate_,
                           data_->isolate_->GetEnteredContext());
 }
 
 
 PerIsolateData::RealmScope::~RealmScope() {
   // Drop realms to avoid keeping them alive.
-  for (int i = 0; i < data_->realm_count_; ++i)
-    data_->realms_[i].Reset();
+  for (int i = 0; i < data_->realm_count_; ++i) {
+    Global<Context>& realm = data_->realms_[i];
+    if (realm.IsEmpty()) continue;
+    DisposeModuleEmbedderData(realm.Get(data_->isolate_));
+    realm.Reset();
+  }
   delete[] data_->realms_;
   if (!data_->realm_shared_.IsEmpty())
     data_->realm_shared_.Reset();
 }
 
 
 int PerIsolateData::RealmFind(Local<Context> context) {
   for (int i = 0; i < realm_count_; ++i) {
     if (realms_[i] == context) return i;
   }
@@ skipping 2073 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif