[ServiceWorkerCacheStorage] Add support for new Open method.

content/browser/service_worker/service_worker_cache_storage.cc

Index: content/browser/service_worker/service_worker_cache_storage.cc
diff --git a/content/browser/service_worker/service_worker_cache_storage.cc b/content/browser/service_worker/service_worker_cache_storage.cc
index 758a124acee71d97c1c8380975cb709347f8a693..1fd5b76ceca04b7ee1a795c2e60eb1efcabab6cb 100644
--- a/content/browser/service_worker/service_worker_cache_storage.cc
+++ b/content/browser/service_worker/service_worker_cache_storage.cc
@@ -376,6 +376,33 @@ void ServiceWorkerCacheStorage::CreateCache(
                  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) {