Add support for using AMD modules from extensions modules.

extensions/renderer/v8_schema_registry.cc

Index: extensions/renderer/v8_schema_registry.cc
diff --git a/extensions/renderer/v8_schema_registry.cc b/extensions/renderer/v8_schema_registry.cc
index 77a91f698514d1db4bc668b967b950c9547e3fb7..33163138cc335ac2a74e4ab1abb96aa592764241 100644
--- a/extensions/renderer/v8_schema_registry.cc
+++ b/extensions/renderer/v8_schema_registry.cc
@@ -105,13 +105,13 @@ v8::Handle<v8::Context> V8SchemaRegistry::GetOrCreateContext(
     v8::Isolate* isolate) {
   // It's ok to create local handles in this function, since this is only called
   // when we have a HandleScope.
-  if (context_.IsEmpty()) {
-    v8::Handle<v8::Context> context = v8::Context::New(isolate);
-    context_.reset(context);
+  if (!context_holder_) {
+    context_holder_.reset(new gin::ContextHolder(isolate));
+    context_holder_->SetContext(v8::Context::New(isolate));
     schema_cache_.reset(new SchemaCache(isolate));
-    return context;
+    return context_holder_->context();
   }
-  return context_.NewHandle(isolate);
+  return context_holder_->context();
 }
 
 }  // namespace extensions