[ServiceWorkerCache] Put should replace an existing entry to meet spec.

content/browser/service_worker/service_worker_cache.cc

Index: content/browser/service_worker/service_worker_cache.cc
diff --git a/content/browser/service_worker/service_worker_cache.cc b/content/browser/service_worker/service_worker_cache.cc
index fbebdc1be21bbf91c8f635814b53f7618defad7a..93a50ba66a17393ff2a6b04db8e64b6d3edc76ff 100644
--- a/content/browser/service_worker/service_worker_cache.cc
+++ b/content/browser/service_worker/service_worker_cache.cc
@@ -817,6 +817,26 @@ void ServiceWorkerCache::PutImpl(scoped_ptr<PutContext> put_context) {
     return;
   }
 
+  ServiceWorkerFetchRequest* request_ptr = put_context->request.get();
+  disk_cache::Backend* backend_ptr = put_context->cache->backend_.get();
+
+  net::CompletionCallback doom_entry_callback =
+      base::Bind(PutDidDoomEntry, base::Passed(put_context.Pass()));
+
+  int rv = backend_ptr->DoomEntry(request_ptr->url.spec(), doom_entry_callback);
+  if (rv != net::ERR_IO_PENDING)
+    doom_entry_callback.Run(rv);
+}
+
+// static
+void ServiceWorkerCache::PutDidDoomEntry(scoped_ptr<PutContext> put_context,
+                                         int doom_rv) {
+  if (!put_context->cache || !put_context->cache->backend_) {
+    put_context->callback.Run(ErrorTypeStorage,
+                              scoped_ptr<ServiceWorkerResponse>(),
+                              scoped_ptr<storage::BlobDataHandle>());
+  }
+
   disk_cache::Entry** entry_ptr = &put_context->cache_entry;
   ServiceWorkerFetchRequest* request_ptr = put_context->request.get();
   disk_cache::Backend* backend_ptr = put_context->cache->backend_.get();