Service Worker: Expose Get/Store/ClearUserData to content layer.

content/public/browser/service_worker_context.h

Index: content/public/browser/service_worker_context.h
diff --git a/content/public/browser/service_worker_context.h b/content/public/browser/service_worker_context.h
index 22c989b4ce8254ddfd423421af59aec9cec2f69c..fa6bcad3f4c9afac4ad422f3bfea71fca9cf6e8a 100644
--- a/content/public/browser/service_worker_context.h
+++ b/content/public/browser/service_worker_context.h
@@ -29,6 +29,10 @@ class ServiceWorkerContext {
 
   typedef base::Callback<void(bool success)> ResultCallback;
 
+  typedef base::Callback<void(const std::string& data,
+                              bool success,
+                              bool not_found)> GetUserDataCallback;
+
   typedef base::Callback<void(const std::vector<ServiceWorkerUsageInfo>&
                                   usage_info)> GetUsageInfoCallback;
 
@@ -71,6 +75,22 @@ class ServiceWorkerContext {
   virtual void UnregisterServiceWorker(const Scope& pattern,
                                        const ResultCallback& callback) = 0;
 
+  // Provide a storage mechanism to read/write arbitrary data associated with
+  // a registration. Each registration has its own key namespace. Stored data
+  // is deleted when the associated registraton is deleted. Must all be called
+  // from the IO thread.
+  virtual void GetUserData(int64 registration_id,
+                           const std::string& key,
+                           const GetUserDataCallback& callback) = 0;
+  virtual void StoreUserData(int64 registration_id,
+                             const GURL& origin,
+                             const std::string& key,
+                             const std::string& data,
+                             const ResultCallback& callback) = 0;
+  virtual void ClearUserData(int64 registration_id,
+                             const std::string& key,
+                             const ResultCallback& callback) = 0;
+
   // TODO(jyasskin): Provide a way to SendMessage to a Scope.
 
   // Determines if a request for 'url' can be satisfied while offline.