Reland of "Introducing the WebServiceWorkerCache."

public/platform/WebServiceWorkerCacheStorage.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebServiceWorkerCacheStorage_h
 #define WebServiceWorkerCacheStorage_h
 
 #include "WebCommon.h"
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebServiceWorkerCacheError.h"
 #include "public/platform/WebString.h"
 #include "public/platform/WebVector.h"
 
 namespace blink {
 
 class WebServiceWorkerCache;
 
-// An interface to the CacheStorage API, implemented by the embedder and passed in to blink. Blink's implementation
+// An interface to the CacheStorage API, implemented by the embedder and passed in to Blink. Blink's implementation
 // of the ServiceWorker spec will call these methods to create/open caches, and expect callbacks from the embedder
 // after operations complete.
 class WebServiceWorkerCacheStorage {
 public:
     typedef WebCallbacks<void, WebServiceWorkerCacheError> CacheStorageCallbacks;
     typedef WebCallbacks<WebServiceWorkerCache, WebServiceWorkerCacheError> CacheStorageWithCacheCallbacks;
     typedef WebCallbacks<WebVector<WebString>, WebServiceWorkerCacheError> CacheStorageKeysCallbacks;
 
     virtual ~WebServiceWorkerCacheStorage() { }
 
-    // Ownership of the CacheStorage*Callbacks methods passes to the WebServiceWorkerCacheStorage
-    // instance, which will delete it after calling onSuccess or onFailure.
+    // Ownership of the CacheStorage*Callbacks methods passes to the WebServiceWorkerCacheStorage instance, which
+    // will delete it after calling onSuccess or onFailure.
+
+    // dispatchGet() or dispatchCreate() can return a WebServiceWorkerCache object, and these objects are owned by
+    // Blink, and should be destroyed when they are no longer needed.
     virtual void dispatchGet(CacheStorageWithCacheCallbacks*, const WebString& cacheName) = 0;
     virtual void dispatchHas(CacheStorageCallbacks*, const WebString& cacheName) = 0;
     virtual void dispatchCreate(CacheStorageWithCacheCallbacks*, const WebString& cacheName) = 0;
     virtual void dispatchDelete(CacheStorageCallbacks*, const WebString& cacheName) = 0;
     virtual void dispatchKeys(CacheStorageKeysCallbacks*) = 0;
 };
 
 } // namespace blink
 
 #endif // WebServiceWorkerCacheStorage_h