Cherry pick http://codereview.chromium.org/1207003/show

Implement support for reattaching a global object to a context. This
can be used to use the same global object for different contexts at
different points in time.

Needed to fix b: 2533219

Change-Id: Ib3b0d35f6ce3e0a5f4b8e54561ba2e99a9ab0ab1

3 files changed, 24 insertions, 0 deletions

diff --git a/src/api.cc b/src/api.cc
index 262bf528..22c5b77b 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -3007,6 +3007,16 @@ void Context::DetachGlobal() {
 }
 
 
+void Context::ReattachGlobal(Handle<Object> global_object) {
+  if (IsDeadCheck("v8::Context::ReattachGlobal()")) return;
+  ENTER_V8;
+  i::Object** ctx = reinterpret_cast<i::Object**>(this);
+  i::Handle<i::Context> context =
+      i::Handle<i::Context>::cast(i::Handle<i::Object>(ctx));
+  i::Bootstrapper::ReattachGlobal(context, Utils::OpenHandle(*global_object));
+}
+
+
 Local<v8::Object> ObjectTemplate::NewInstance() {
   ON_BAILOUT("v8::ObjectTemplate::NewInstance()", return Local<v8::Object>());
   LOG_API("ObjectTemplate::NewInstance");
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 6e565e08..225865cf 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -315,6 +315,17 @@ void Bootstrapper::DetachGlobal(Handle<Context> env) {
 }
 
 
+void Bootstrapper::ReattachGlobal(Handle<Context> env,
+                                  Handle<Object> global_object) {
+  ASSERT(global_object->IsJSGlobalProxy());
+  Handle<JSGlobalProxy> global = Handle<JSGlobalProxy>::cast(global_object);
+  env->global()->set_global_receiver(*global);
+  env->set_global_proxy(*global);
+  SetObjectPrototype(global, Handle<JSObject>(env->global()));
+  global->set_context(*env);
+}
+
+
 static Handle<JSFunction> InstallFunction(Handle<JSObject> target,
                                           const char* name,
                                           InstanceType type,
diff --git a/src/bootstrapper.h b/src/bootstrapper.h
index f905a28b..89eb381b 100644
--- a/src/bootstrapper.h
+++ b/src/bootstrapper.h
@@ -68,6 +68,9 @@ class Bootstrapper : public AllStatic {
   // Detach the environment from its outer global object.
   static void DetachGlobal(Handle<Context> env);
 
+  // Reattach an outer global object to an environment.
+  static void ReattachGlobal(Handle<Context> env, Handle<Object> global_object);
+
   // Traverses the pointers for memory management.
   static void Iterate(ObjectVisitor* v);