[Extensions Bindings] Add support for updateArgumentsPreValidate

extensions/renderer/native_extension_bindings_system.cc

Index: extensions/renderer/native_extension_bindings_system.cc
diff --git a/extensions/renderer/native_extension_bindings_system.cc b/extensions/renderer/native_extension_bindings_system.cc
index 0669c14dc3e52108856cc791769a6304f4a7f371..a67b01180d520099d04c81c1afe94ce949da339d 100644
--- a/extensions/renderer/native_extension_bindings_system.cc
+++ b/extensions/renderer/native_extension_bindings_system.cc
@@ -81,6 +81,52 @@ void CallJsFunction(v8::Local<v8::Function> function,
   script_context->SafeCallFunction(function, argc, argv);
 }
 
+// A helper class for calling JS function synchronously.
+class CallJsSyncHelper {
+ public:
+  CallJsSyncHelper(v8::Isolate* isolate) : isolate_(isolate),
+                                           weak_factory_(this) {}
+  ~CallJsSyncHelper() {}
+
+  ScriptInjectionCallback::CompleteCallback GetCallback() {
+    return base::Bind(&CallJsSyncHelper::OnJsComplete,
+                      weak_factory_.GetWeakPtr());
+  }
+
+  bool did_complete() const { return did_complete_; }
+  v8::Global<v8::Value> take_result() { return std::move(result_); }
+
+ private:
+  void OnJsComplete(const std::vector<v8::Local<v8::Value>>& results) {
+    DCHECK_EQ(1u, results.size());
+    did_complete_ = true;
+    // The locals are released after the callback is executed, so we need to
+    // grab a persistent handle.
+    result_.Reset(isolate_, results[0]);
+  }
+
+  bool did_complete_ = false;
+  v8::Isolate* isolate_;
+  v8::Global<v8::Value> result_;
+  base::WeakPtrFactory<CallJsSyncHelper> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CallJsSyncHelper);
+};
+
+v8::Global<v8::Value> CallJsFunctionSync(v8::Local<v8::Function> function,
+                                         v8::Local<v8::Context> context,
+                                         int argc,
+                                         v8::Local<v8::Value> argv[]) {
+  CallJsSyncHelper helper(context->GetIsolate());
+  ScriptContext* script_context =
+      ScriptContextSet::GetContextByV8Context(context);
+  CHECK(script_context);
+  script_context->SafeCallFunction(function, argc, argv, helper.GetCallback());
+  // If the JS did not, in fact, execute synchronously, there's a big problem.
+  CHECK(helper.did_complete());
+  return helper.take_result();
+}
+
 // Returns the API schema indicated by |api_name|.
 const base::DictionaryValue& GetAPISchema(const std::string& api_name) {
   const base::DictionaryValue* schema =
@@ -102,6 +148,7 @@ NativeExtensionBindingsSystem::NativeExtensionBindingsSystem(
     const SendIPCMethod& send_ipc)
     : send_ipc_(send_ipc),
       api_system_(base::Bind(&CallJsFunction),
+                  base::Bind(&CallJsFunctionSync),
                   base::Bind(&GetAPISchema),
                   base::Bind(&NativeExtensionBindingsSystem::SendRequest,
                              base::Unretained(this))),