Rename "register" -> "subscribe" in the Push Messaging code.

content/public/browser/push_messaging_service.cc

Index: content/public/browser/push_messaging_service.cc
diff --git a/content/public/browser/push_messaging_service.cc b/content/public/browser/push_messaging_service.cc
index 27335eb9adfbab9ca60bce7e78f50ae897fd6bb2..fd990c504ffba5b071fa4291d6200754795e7e06 100644
--- a/content/public/browser/push_messaging_service.cc
+++ b/content/public/browser/push_messaging_service.cc
@@ -67,7 +67,7 @@ void SetNotificationsShownOnIO(
       base::Bind(&CallResultCallbackFromIO, callback));
 }
 
-void ClearPushRegistrationIDOnIO(
+void ClearPushSubscriptionIDOnIO(
     scoped_refptr<ServiceWorkerContextWrapper> service_worker_context,
     int64 service_worker_registration_id,
     const base::Closure& callback) {
@@ -75,7 +75,7 @@ void ClearPushRegistrationIDOnIO(
 
   service_worker_context->ClearRegistrationUserData(
       service_worker_registration_id,
-      kPushRegistrationIdServiceWorkerKey,
+      kPushSubscriptionIdServiceWorkerKey,
       base::Bind(&CallClosureFromIO, callback));
 }
 
@@ -142,7 +142,7 @@ void PushMessagingService::GetSenderId(BrowserContext* browser_context,
 }
 
 // static
-void PushMessagingService::ClearPushRegistrationID(
+void PushMessagingService::ClearPushSubscriptionID(
     BrowserContext* browser_context,
     const GURL& origin,
     int64 service_worker_registration_id,
@@ -151,7 +151,7 @@ void PushMessagingService::ClearPushRegistrationID(
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
-      base::Bind(&ClearPushRegistrationIDOnIO,
+      base::Bind(&ClearPushSubscriptionIDOnIO,
                  GetServiceWorkerContext(browser_context, origin),
                  service_worker_registration_id,
                  callback));