[ServiceWorkerCacheStorage] Add support for new Open method.

content/browser/service_worker/service_worker_cache_storage.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_cache_storage.h"
 
 #include <string>
 
 #include "base/files/file_util.h"
 #include "base/files/memory_mapped_file.h"
@@ skipping 358 matching lines @@
   }
 
   cache_loader_->CreateCache(
       cache_name,
       base::Bind(&ServiceWorkerCacheStorage::CreateCacheDidCreateCache,
                  weak_factory_.GetWeakPtr(),
                  cache_name,
                  callback));
 }
 
+void ServiceWorkerCacheStorage::OpenCache(
+    const std::string& cache_name,
+    const CacheAndErrorCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (!initialized_) {
+    LazyInit(base::Bind(&ServiceWorkerCacheStorage::OpenCache,
+                        weak_factory_.GetWeakPtr(),
+                        cache_name,
+                        callback));
+    return;
+  }
+
+  scoped_refptr<ServiceWorkerCache> cache = GetLoadedCache(cache_name);
+  if (cache.get()) {
+    callback.Run(cache, CACHE_STORAGE_ERROR_NO_ERROR);
+    return;
+  }
+
+  cache_loader_->CreateCache(
+      cache_name,
+      base::Bind(&ServiceWorkerCacheStorage::CreateCacheDidCreateCache,
+                 weak_factory_.GetWeakPtr(),
+                 cache_name,
+                 callback));
+}
+
 void ServiceWorkerCacheStorage::GetCache(
     const std::string& cache_name,
     const CacheAndErrorCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (!initialized_) {
     LazyInit(base::Bind(&ServiceWorkerCacheStorage::GetCache,
                         weak_factory_.GetWeakPtr(),
                         cache_name,
                         callback));
@@ skipping 197 matching lines @@
     scoped_refptr<ServiceWorkerCache> new_cache =
         cache_loader_->CreateServiceWorkerCache(cache_name);
     map_iter->second = new_cache->AsWeakPtr();
     return new_cache;
   }
 
   return make_scoped_refptr(cache.get());
 }
 
 }  // namespace content