Adds a basic offline check to InstallableManager.

content/public/browser/service_worker_context.h

Index: content/public/browser/service_worker_context.h
diff --git a/content/public/browser/service_worker_context.h b/content/public/browser/service_worker_context.h
index c095f9d1314c7fe028441bb19479c2f73d4fc99e..cc5164ad4952c964dcc9dc683904e3978ec5dd7e 100644
--- a/content/public/browser/service_worker_context.h
+++ b/content/public/browser/service_worker_context.h
@@ -18,6 +18,12 @@ enum class WebNavigationHintType;
 
 namespace content {
 
+enum class ServiceWorkerStatus {
+  NO_SERVICE_WORKER,
+  SERVICE_WORKER_NO_FETCH_HANDLER,
+  SERVICE_WORKER_WITH_FETCH_HANDLER,
+};
+
 // Represents the per-StoragePartition ServiceWorker data.
 class ServiceWorkerContext {
  public:
@@ -30,8 +36,8 @@ class ServiceWorkerContext {
   using GetUsageInfoCallback = base::Callback<void(
       const std::vector<ServiceWorkerUsageInfo>& usage_info)>;
 
-  using CheckHasServiceWorkerCallback =
-      base::Callback<void(bool has_service_worker)>;
+  using CheckServiceWorkerStatusCallback =
+      base::Callback<void(ServiceWorkerStatus sw_status)>;
 
   using CountExternalRequestsCallback =
       base::Callback<void(size_t external_request_count)>;
@@ -109,10 +115,10 @@ class ServiceWorkerContext {
   //
   // This function can be called from any thread, but the callback will always
   // be called on the UI thread.
-  virtual void CheckHasServiceWorker(
+  virtual void CheckServiceWorkerStatus(
       const GURL& url,
       const GURL& other_url,
-      const CheckHasServiceWorkerCallback& callback) = 0;
+      const CheckServiceWorkerStatusCallback& callback) = 0;
 
   // Returns the pending external request count for the worker with the
   // specified |origin| via |callback|.