Revert of service worker: use 200 OK for update requests even in the no update case

content/browser/service_worker/service_worker_write_to_cache_job.cc

Index: content/browser/service_worker/service_worker_write_to_cache_job.cc
diff --git a/content/browser/service_worker/service_worker_write_to_cache_job.cc b/content/browser/service_worker/service_worker_write_to_cache_job.cc
index 8c6148f8ac98720d34c635f91236b15317026530..b5477ab9a0195958a0be000ce5961f312dd8f918 100644
--- a/content/browser/service_worker/service_worker_write_to_cache_job.cc
+++ b/content/browser/service_worker/service_worker_write_to_cache_job.cc
@@ -41,10 +41,16 @@
     "The script resource is behind a redirect, which is disallowed.";
 const char kServiceWorkerAllowed[] = "Service-Worker-Allowed";
 
+// The net error code used when the job fails the update attempt because the new
+// script is byte-by-byte identical to the incumbent script. This error is shown
+// in DevTools and in netlog, so we want something obscure enough that it won't
+// conflict with a legitimate network error, and not too alarming if seen by
+// developers.
+// TODO(falken): Redesign this class so we don't have to fail at the network
+// stack layer just to cancel the update.
+const net::Error kIdenticalScriptError = net::ERR_FILE_EXISTS;
+
 }  // namespace
-
-const net::Error ServiceWorkerWriteToCacheJob::kIdenticalScriptError =
-    net::ERR_FILE_EXISTS;
 
 ServiceWorkerWriteToCacheJob::ServiceWorkerWriteToCacheJob(
     net::URLRequest* request,
@@ -466,7 +472,8 @@
   // exists.
   if (status.status() == net::URLRequestStatus::SUCCESS &&
       !cache_writer_->did_replace()) {
-    status = net::URLRequestStatus::FromError(kIdenticalScriptError);
+    result = kIdenticalScriptError;
+    status = net::URLRequestStatus::FromError(result);
     version_->SetStartWorkerStatusCode(SERVICE_WORKER_ERROR_EXISTS);
     version_->script_cache_map()->NotifyFinishedCaching(url_, size, status,
                                                         std::string());
@@ -482,7 +489,7 @@
 scoped_ptr<ServiceWorkerResponseReader>
 ServiceWorkerWriteToCacheJob::CreateCacheResponseReader() {
   if (incumbent_resource_id_ == kInvalidServiceWorkerResourceId ||
-      !version_->pause_after_download()) {
+      version_->skip_script_comparison()) {
     return nullptr;
   }
   return context_->storage()->CreateResponseReader(incumbent_resource_id_);