[Extensions Bindings] Add chrome.runtime.lastError support

extensions/renderer/api_request_handler.cc

 // Copyright 2016 The Chromium 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 "extensions/renderer/api_request_handler.h"
 
 #include "base/bind.h"
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
@@ skipping 12 matching lines @@
     for (const auto& arg : local_callback_args)
       callback_arguments.push_back(v8::Global<v8::Value>(isolate, arg));
   }
 }
 
 APIRequestHandler::PendingRequest::~PendingRequest() {}
 APIRequestHandler::PendingRequest::PendingRequest(PendingRequest&&) = default;
 APIRequestHandler::PendingRequest& APIRequestHandler::PendingRequest::operator=(
     PendingRequest&&) = default;
 
-APIRequestHandler::APIRequestHandler(const CallJSFunction& call_js)
-    : call_js_(call_js) {}
+APIRequestHandler::APIRequestHandler(const CallJSFunction& call_js,
+                                     APILastError last_error)
+    : call_js_(call_js), last_error_(std::move(last_error)) {}
 
 APIRequestHandler::~APIRequestHandler() {}
 
 int APIRequestHandler::AddPendingRequest(
     v8::Isolate* isolate,
     v8::Local<v8::Function> callback,
     v8::Local<v8::Context> context,
     const std::vector<v8::Local<v8::Value>>& callback_args) {
   // TODO(devlin): We could *probably* get away with just using an integer here,
   // but it's a little less foolproof. How slow is GenerateGUID? Should we use
   // that instead? It means updating the IPC (ExtensionHostMsg_Request).
   // base::UnguessableToken is another good option.
   int id = next_request_id_++;
   pending_requests_.insert(std::make_pair(
       id, PendingRequest(isolate, callback, context, callback_args)));
   return id;
 }
 
 void APIRequestHandler::CompleteRequest(int request_id,
-                                        const base::ListValue& response_args) {
+                                        const base::ListValue& response_args,
+                                        const std::string& error) {
   auto iter = pending_requests_.find(request_id);
   // The request may have been removed if the context was invalidated before a
   // response is ready.
   if (iter == pending_requests_.end())
     return;
 
   PendingRequest pending_request = std::move(iter->second);
   pending_requests_.erase(iter);
 
   v8::Isolate* isolate = pending_request.isolate;
   v8::HandleScope handle_scope(isolate);
   v8::Local<v8::Context> context = pending_request.context.Get(isolate);
+  v8::Context::Scope context_scope(context);
   std::unique_ptr<content::V8ValueConverter> converter(
       content::V8ValueConverter::create());
   std::vector<v8::Local<v8::Value>> args;
   args.reserve(response_args.GetSize() +
                pending_request.callback_arguments.size());
   for (const auto& arg : pending_request.callback_arguments)
     args.push_back(arg.Get(isolate));
   for (const auto& arg : response_args)
     args.push_back(converter->ToV8Value(arg.get(), context));
 
+  if (!error.empty())
+    last_error_.SetError(context, error);
+
   // args.size() is converted to int, but args is controlled by chrome and is
   // never close to std::numeric_limits<int>::max.
   call_js_.Run(pending_request.callback.Get(isolate), context, args.size(),
                args.data());
+
+  if (!error.empty())
+    last_error_.ClearError(context, true);
 }
 
 void APIRequestHandler::InvalidateContext(v8::Local<v8::Context> context) {
   for (auto iter = pending_requests_.begin();
        iter != pending_requests_.end();) {
     if (iter->second.context == context)
       iter = pending_requests_.erase(iter);
     else
       ++iter;
   }
 }
 
 std::set<int> APIRequestHandler::GetPendingRequestIdsForTesting() const {
   std::set<int> result;
   for (const auto& pair : pending_requests_)
     result.insert(pair.first);
   return result;
 }
 
 }  // namespace extensions