Implement updateViaCache flag and no-cache by default for main service worker scripts

content/browser/service_worker/service_worker_context_request_handler.cc

Index: content/browser/service_worker/service_worker_context_request_handler.cc
diff --git a/content/browser/service_worker/service_worker_context_request_handler.cc b/content/browser/service_worker/service_worker_context_request_handler.cc
index 4b3535aa5b9eaa18502b95b6ddf4e927b381a90a..b42ae219d75ecfd1feb5f604630d55126ecc14a1 100644
--- a/content/browser/service_worker/service_worker_context_request_handler.cc
+++ b/content/browser/service_worker/service_worker_context_request_handler.cc
@@ -21,6 +21,18 @@
 
 namespace content {
 
+namespace {
+bool ShouldBypassCache(bool is_main_script,
+                       blink::WebServiceWorkerUpdateViaCache cache_mode) {
+  if (is_main_script &&
+      cache_mode != blink::WebServiceWorkerUpdateViaCache::kAll)
+    return true;
+  if (cache_mode == blink::WebServiceWorkerUpdateViaCache::kNone)
+    return true;
+  return false;
+}
+}  // namespace
+
 ServiceWorkerContextRequestHandler::ServiceWorkerContextRequestHandler(
     base::WeakPtr<ServiceWorkerContextCore> context,
     base::WeakPtr<ServiceWorkerProviderHost> provider_host,
@@ -191,7 +203,9 @@ net::URLRequestJob* ServiceWorkerContextRequestHandler::MaybeCreateJobImpl(
   int extra_load_flags = 0;
   base::TimeDelta time_since_last_check =
       base::Time::Now() - registration->last_update_check();
-  if (time_since_last_check > kServiceWorkerScriptMaxCacheAge ||
+
+  if (ShouldBypassCache(is_main_script, registration->update_via_cache()) ||
+      time_since_last_check > kServiceWorkerScriptMaxCacheAge ||
       version_->force_bypass_cache_for_scripts()) {
     extra_load_flags = net::LOAD_BYPASS_CACHE;
   }