Tidy up CompositorWorkerManager unit tests.

Source/modules/filesystem/LocalFileSystem.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 186 matching lines @@
 {
 }
 
 const char* LocalFileSystem::supplementName()
 {
     return "LocalFileSystem";
 }
 
 LocalFileSystem* LocalFileSystem::from(ExecutionContext& context)
 {
-    if (context.isDocument()) {
+    if (context.isDocument())
         return static_cast<LocalFileSystem*>(WillBeHeapSupplement<LocalFrame>::from(toDocument(context).frame(), supplementName()));
-    }
+
     ASSERT(context.isWorkerGlobalScope());
-    return static_cast<LocalFileSystem*>(WillBeHeapSupplement<WorkerClients>::from(toWorkerGlobalScope(context).clients(), supplementName()));
+    WorkerClients* clients = toWorkerGlobalScope(context).clients();
+    ASSERT(clients);
+    return static_cast<LocalFileSystem*>(WillBeHeapSupplement<WorkerClients>::from(clients, supplementName()));
 }
 
 void provideLocalFileSystemTo(LocalFrame& frame, PassOwnPtr<FileSystemClient> client)
 {
     frame.provideSupplement(LocalFileSystem::supplementName(), LocalFileSystem::create(client));
 }
 
 void provideLocalFileSystemToWorker(WorkerClients* clients, PassOwnPtr<FileSystemClient> client)
 {
     clients->provideSupplement(LocalFileSystem::supplementName(), LocalFileSystem::create(client));
 }
 
 } // namespace blink