add error IPC handling to dispatcher

content/child/service_worker/service_worker_dispatcher.cc

Index: content/child/service_worker/service_worker_dispatcher.cc
diff --git a/content/child/service_worker/service_worker_dispatcher.cc b/content/child/service_worker/service_worker_dispatcher.cc
index c2c75b410c98688a0e5182e9c00be20dd98d009a..0658bae6ad93e089a6bcfbd7aa0cccfbcd7c8ddc 100644
--- a/content/child/service_worker/service_worker_dispatcher.cc
+++ b/content/child/service_worker/service_worker_dispatcher.cc
@@ -36,10 +36,11 @@ ServiceWorkerDispatcher::~ServiceWorkerDispatcher() {
 void ServiceWorkerDispatcher::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ServiceWorkerDispatcher, msg)
-    IPC_MESSAGE_HANDLER(ServiceWorkerMsg_ServiceWorkerRegistered,
-                        OnServiceWorkerRegistered)
+    IPC_MESSAGE_HANDLER(ServiceWorkerMsg_ServiceWorkerRegistered, OnRegistered)
     IPC_MESSAGE_HANDLER(ServiceWorkerMsg_ServiceWorkerUnregistered,
-                        OnServiceWorkerUnregistered)
+                        OnUnregistered)
+    IPC_MESSAGE_HANDLER(ServiceWorkerMsg_ServiceWorkerRegistrationError,
+                        OnRegistrationError)

[kinuko, 2013/10/10 07:57:22]

Any particular reason we use a separate IPC for errors? There's a pros/cons
though either way works.

Say, if we're going to add a new IPC request which would just return success or
fail in this family (I had imagined that unregisterSW might fall into this
category), are we going to add OnSuccess IPC?

[michaeln, 2013/10/11 01:29:12]

Either way does work. I was expecting register/registercomplete +
unregister/unregistercomplete pairing of messages. The pros to me are that it's
more obvious whats going on at each step of the way... 
- when looking at the ipc message .h
- when looking at the onxxxcomplete handler, you see all possible complete paths
- its more clear what to do in the "please do it" handler what needs to be done
to complete the call
- its more clear what to do when adding a new request/response type

Fair to say i have a preference for foo/fooresult, bar/barresult pairs.

     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   DCHECK(handled) << "Unhandled message:" << msg.type();
@@ -90,10 +91,9 @@ ServiceWorkerDispatcher* ServiceWorkerDispatcher::ThreadSpecificInstance(
   return dispatcher;
 }
 
-void ServiceWorkerDispatcher::OnServiceWorkerRegistered(
-    int32 thread_id,
-    int32 request_id,
-    int32 service_worker_id) {
+void ServiceWorkerDispatcher::OnRegistered(int32 thread_id,
+                                           int32 request_id,
+                                           int32 service_worker_id) {
   WebServiceWorkerProvider::WebServiceWorkerCallbacks* callbacks =
       pending_callbacks_.Lookup(request_id);
   DCHECK(callbacks);
@@ -112,10 +112,9 @@ void ServiceWorkerDispatcher::OnServiceWorkerRegistered(
   pending_callbacks_.Remove(request_id);
 }
 
-void ServiceWorkerDispatcher::OnServiceWorkerUnregistered(
-    int32 thread_id,
-    int32 request_id,
-    int32 service_worker_id) {
+void ServiceWorkerDispatcher::OnUnregistered(int32 thread_id,
+                                             int32 request_id,
+                                             int32 service_worker_id) {
   WebServiceWorkerProvider::WebServiceWorkerCallbacks* callbacks =
       pending_callbacks_.Lookup(request_id);
   DCHECK(callbacks);
@@ -129,6 +128,18 @@ void ServiceWorkerDispatcher::OnServiceWorkerUnregistered(
   pending_callbacks_.Remove(request_id);
 }
 
+void ServiceWorkerDispatcher::OnRegistrationError(int32 thread_id,
+                                                  int32 request_id) {
+  WebServiceWorkerProvider::WebServiceWorkerCallbacks* callbacks =
+      pending_callbacks_.Lookup(request_id);
+  DCHECK(callbacks);
+  if (!callbacks)
+    return;
+
+  callbacks->onError(NULL);

[kinuko, 2013/10/10 07:57:22]

Looks like this method expects WebSW ptr type for now, while this should
probably be evolved to pass something like WebServiceWorkerErrorReason?

https://github.com/slightlyoff/ServiceWorker/blob/master/service_worker.ts#L29

+  pending_callbacks_.Remove(request_id);
+}
+
 void ServiceWorkerDispatcher::OnWorkerRunLoopStopped() { delete this; }
 
 }  // namespace content