ServiceWorker: Add initial implementation of ExtendableMessageEvent behind a flag

content/common/service_worker/service_worker_messages.h

Index: content/common/service_worker/service_worker_messages.h
diff --git a/content/common/service_worker/service_worker_messages.h b/content/common/service_worker/service_worker_messages.h
index 929ff7d85e9f9c817bb856af83cac2e27bd36a05..0cc382d2d64cfd7ab023568d8b5725510b44300c 100644
--- a/content/common/service_worker/service_worker_messages.h
+++ b/content/common/service_worker/service_worker_messages.h
@@ -181,13 +181,22 @@ IPC_MESSAGE_CONTROL3(ServiceWorkerHostMsg_GetRegistrationForReady,
                      int /* request_id */,
                      int /* provider_id */)
 
-// Sends a 'message' event to a service worker (renderer->browser).
+// Sends ExtendableMessageEvent to a service worker (renderer->browser).
 IPC_MESSAGE_CONTROL3(
     ServiceWorkerHostMsg_PostMessageToWorker,
     int /* handle_id */,
     base::string16 /* message */,
     std::vector<content::TransferredMessagePort> /* sent_message_ports */)
 
+// Sends MessageEvent to a service worker (renderer->browser).
+// TODO(nhiroki): Remove this after ExtendableMessageEvent is enabled by
+// default (crbug.com/543198).
+IPC_MESSAGE_CONTROL3(
+    ServiceWorkerHostMsg_DeprecatedPostMessageToWorker,
+    int /* handle_id */,
+    base::string16 /* message */,
+    std::vector<content::TransferredMessagePort> /* sent_message_ports */)
+
 // Informs the browser of a new ServiceWorkerProvider in the child process,
 // |provider_id| is unique within its child process. When this provider is
 // created for a document, |route_id| is the frame ID of it. When this provider
@@ -241,6 +250,9 @@ IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_InstallEventFinished,
 IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_ActivateEventFinished,
                     int /* request_id */,
                     blink::WebServiceWorkerEventResult)
+IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_ExtendableMessageEventFinished,
+                    int /* request_id */,
+                    blink::WebServiceWorkerEventResult)
 IPC_MESSAGE_ROUTED3(ServiceWorkerHostMsg_FetchEventFinished,
                     int /* request_id */,
                     content::ServiceWorkerFetchEventResult,
@@ -264,7 +276,7 @@ IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_GetClients,
                     int /* request_id */,
                     content::ServiceWorkerClientQueryOptions)
 
-// Sends a 'message' event to a client (renderer->browser).
+// Sends MessageEvent to a client (renderer->browser).
 IPC_MESSAGE_ROUTED3(
     ServiceWorkerHostMsg_PostMessageToClient,
     std::string /* uuid */,
@@ -436,7 +448,7 @@ IPC_MESSAGE_CONTROL4(ServiceWorkerMsg_SetControllerServiceWorker,
                      content::ServiceWorkerObjectInfo,
                      bool /* should_notify_controllerchange */)
 
-// Sends a 'message' event to a client document (browser->renderer).
+// Sends MessageEvent to a client document (browser->renderer).
 IPC_MESSAGE_CONTROL1(ServiceWorkerMsg_MessageToDocument,
                      ServiceWorkerMsg_MessageToDocument_Params)
 
@@ -445,6 +457,12 @@ IPC_MESSAGE_CONTROL1(ServiceWorkerMsg_InstallEvent,
                      int /* request_id */)
 IPC_MESSAGE_CONTROL1(ServiceWorkerMsg_ActivateEvent,
                      int /* request_id */)
+IPC_MESSAGE_CONTROL4(
+    ServiceWorkerMsg_ExtendableMessageEvent,
+    int /* request_id */,
+    base::string16 /* message */,
+    std::vector<content::TransferredMessagePort> /* sent_message_ports */,
+    std::vector<int> /* new_routing_ids */)
 IPC_MESSAGE_CONTROL2(ServiceWorkerMsg_FetchEvent,
                      int /* request_id */,
                      content::ServiceWorkerFetchRequest)
@@ -461,11 +479,15 @@ IPC_MESSAGE_CONTROL4(ServiceWorkerMsg_GeofencingEvent,
                      blink::WebGeofencingEventType /* event_type */,
                      std::string /* region_id */,
                      blink::WebCircularGeofencingRegion /* region */)
+
+// TODO(nhiroki): Remove this after ExtendableMessageEvent is enabled by
+// default (crbug.com/543198).
 IPC_MESSAGE_CONTROL3(
     ServiceWorkerMsg_MessageToWorker,
     base::string16 /* message */,
     std::vector<content::TransferredMessagePort> /* sent_message_ports */,
     std::vector<int> /* new_routing_ids */)
+
 IPC_MESSAGE_CONTROL4(
     ServiceWorkerMsg_CrossOriginMessageToWorker,
     content::NavigatorConnectClient /* client */,