Added support for multiple parameters to Extension API callbacks.

chrome/browser/extensions/extension_function.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/extension_function.h"
 
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "chrome/browser/extensions/extension_function_dispatcher.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 75 matching lines @@
 void ExtensionFunction::OnQuotaExceeded() {
   error_ = QuotaLimitHeuristic::kGenericOverQuotaError;
   SendResponse(false);
 }
 
 void ExtensionFunction::SetArgs(const base::ListValue* args) {
   DCHECK(!args_.get());  // Should only be called once.
   args_.reset(args->DeepCopy());
 }
 
-const Value* ExtensionFunction::GetResultValue() {
-  return result_.get();
+void ExtensionFunction::SetResult(base::Value* result) {
+  results_.reset(new base::ListValue());
+  results_->Append(result);
+}
+
+const ListValue* ExtensionFunction::GetResultList() {
+  return results_.get();
 }
 
 const std::string ExtensionFunction::GetError() {
   return error_;
 }
 
 void ExtensionFunction::SetError(const std::string& error) {
   error_ = error;
 }
 
@@ skipping 14 matching lines @@
 void ExtensionFunction::SendResponseImpl(base::ProcessHandle process,
                                          IPC::Sender* ipc_sender,
                                          int routing_id,
                                          bool success) {
   DCHECK(ipc_sender);
   if (bad_message_) {
     HandleBadMessage(process);
     return;
   }
 
-  // Value objects can't be directly serialized in our IPC code, so we wrap the
-  // result_ Value with a ListValue (also transferring ownership of result_).
-  base::ListValue result_wrapper;
-  if (result_.get())
-    result_wrapper.Append(result_.release());
+  // If results were never set, we send an empty argument list.
+  if (!results_.get())
+    results_.reset(new ListValue());
 
   ipc_sender->Send(new ExtensionMsg_Response(
-      routing_id, request_id_, success, result_wrapper, GetError()));
+      routing_id, request_id_, success, *results_.release(), GetError()));

[koz (OOO until 15th September), 2012/07/13 04:48:16]

Is this a memory leak?

I think a better way to do it would be to have results_ just be a ListValue, not
a scoped_ptr<ListValue>. In SetResult() you can Clear() it, rather than
allocating a new one.

[Matt Tytel, 2012/07/13 05:14:39]

:( Yes that is.

As for the scoped_ptr business, the json schema compiler will (soon) return a
new ListValue for the arguments so it will be useful just to .reset() to that
Value.

[not at google - send to devlin, 2012/07/13 05:20:05]

In the JSC case it's also reasonable to do

void SetResults(scoped_ptr<ListValue> results) {
  results_.Swap(results.get());
}

or whatever equivalent compiles.

 }
 
 void ExtensionFunction::HandleBadMessage(base::ProcessHandle process) {
   LOG(ERROR) << "bad extension message " << name_ << " : terminating renderer.";
   if (content::RenderProcessHost::run_renderer_in_process()) {
     // In single process mode it is better if we don't suicide but just crash.
     CHECK(false);
   } else {
     NOTREACHED();
     content::RecordAction(UserMetricsAction("BadMessageTerminate_EFD"));
@@ skipping 145 matching lines @@
 
 SyncIOThreadExtensionFunction::SyncIOThreadExtensionFunction() {
 }
 
 SyncIOThreadExtensionFunction::~SyncIOThreadExtensionFunction() {
 }
 
 void SyncIOThreadExtensionFunction::Run() {
   SendResponse(RunImpl());
 }