[WIP] [service worker] Fix detach controller and fallback to network mechanism

content/child/service_worker/service_worker_handle_reference.h

Index: content/child/service_worker/service_worker_handle_reference.h
diff --git a/content/child/service_worker/service_worker_handle_reference.h b/content/child/service_worker/service_worker_handle_reference.h
index 81305cd0781f7ef8d26e0be7690112269a826ab2..c81e3ece75d80dc2847a13d6dfe253d98369c06d 100644
--- a/content/child/service_worker/service_worker_handle_reference.h
+++ b/content/child/service_worker/service_worker_handle_reference.h
@@ -19,12 +19,14 @@ class ThreadSafeSender;
 // or decrement the reference count to the browser process.
 class CONTENT_EXPORT ServiceWorkerHandleReference {
  public:
-  // Creates a new ServiceWorkerHandleReference and increments ref-count.
+  // Creates a new ServiceWorkerHandleReference and increments ref-count. If
+  // the handle id is kInvalidServiceWorkerHandleId, returns null instead.
   static scoped_ptr<ServiceWorkerHandleReference> Create(
       const ServiceWorkerObjectInfo& info,
       ThreadSafeSender* sender);
 
-  // Creates a new ServiceWorkerHandleReference by adopting a ref-count.
+  // Creates a new ServiceWorkerHandleReference by adopting a ref-count. If
+  // the handle id is kInvalidServiceWorkerHandleId, returns null instead.
   static scoped_ptr<ServiceWorkerHandleReference> Adopt(
       const ServiceWorkerObjectInfo& info,
       ThreadSafeSender* sender);