[ServiceWorker] Add EmbeddedWorkerInstanceHost Interface.

content/renderer/service_worker/embedded_worker_dispatcher.h

Index: content/renderer/service_worker/embedded_worker_dispatcher.h
diff --git a/content/renderer/service_worker/embedded_worker_dispatcher.h b/content/renderer/service_worker/embedded_worker_dispatcher.h
index c6b6e64ac844f01771f6530dae463e670ced952c..24ec2c14cafb895cc3e422cb2296bd678620c65a 100644
--- a/content/renderer/service_worker/embedded_worker_dispatcher.h
+++ b/content/renderer/service_worker/embedded_worker_dispatcher.h
@@ -13,7 +13,6 @@
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "content/child/scoped_child_process_reference.h"
-#include "ipc/ipc_listener.h"
 
 namespace blink {
 
@@ -28,13 +27,10 @@ class ServiceWorkerContextClient;
 struct EmbeddedWorkerStartParams;
 
 // A tiny dispatcher which handles embedded worker start/stop messages.
-class EmbeddedWorkerDispatcher : public IPC::Listener {
+class EmbeddedWorkerDispatcher {

[shimazu, 2017/04/10 05:09:22]

Sorry for additional comment.
EWDispatcher seems no longer needed. Could you remove this also and move
WorkerWrapper into EWInstanceClient?

[leonhsl(Using Gerrit), 2017/04/10 06:10:36]

Yeah, thank you very much for the confirmation! I had somehow similar feeling
but was not sure so I did not speak out about this ;-) Could we do this work
with a follow-up CL? Because I want to keep this CL to be not so big and its'
goal to be clear. Or do you think we'd better do this together within this CL
because it should be part of this CL's work? I'm happy to follow your opinion.
Thanks!

[shimazu, 2017/04/10 09:33:40]

I'm happy if you would remove this class in this CL because I assume the removal
of this class won't be so big, but I can also take it over if you want.
How will you do? 

[leonhsl(Using Gerrit), 2017/04/10 09:41:00]

Understood, I'd like to do this in this CL :)

  public:
   EmbeddedWorkerDispatcher();
-  ~EmbeddedWorkerDispatcher() override;
-
-  // IPC::Listener overrides.
-  bool OnMessageReceived(const IPC::Message& message) override;
+  ~EmbeddedWorkerDispatcher();
 
   void WorkerContextDestroyed(int embedded_worker_id);
 
@@ -60,8 +56,6 @@ class EmbeddedWorkerDispatcher : public IPC::Listener {
     std::unique_ptr<EmbeddedWorkerDevToolsAgent> devtools_agent_;
   };
 
-  void OnStopWorker(int embedded_worker_id);
-
   std::unique_ptr<WorkerWrapper> StartWorkerContext(
       const EmbeddedWorkerStartParams& params,
       std::unique_ptr<ServiceWorkerContextClient> context_client);