remove use of {,un}setPendingActivity from DOMFileSystem.

Source/modules/filesystem/InspectorFileSystemAgent.cpp

Index: Source/modules/filesystem/InspectorFileSystemAgent.cpp
diff --git a/Source/modules/filesystem/InspectorFileSystemAgent.cpp b/Source/modules/filesystem/InspectorFileSystemAgent.cpp
index bd6247093e6a75beef7a77f7f5921d14ec7658ec..dd6134bfcf68a085f3ab82d71225084dbea2e2c5 100644
--- a/Source/modules/filesystem/InspectorFileSystemAgent.cpp
+++ b/Source/modules/filesystem/InspectorFileSystemAgent.cpp
@@ -565,7 +565,7 @@ void DeleteEntryRequest::start(ExecutionContext* executionContext)
 
     if (path == "/") {
         OwnPtr<VoidCallback> successCallback = adoptPtr(new VoidCallbackImpl(this));
-        OwnPtr<AsyncFileSystemCallbacks> fileSystemCallbacks = VoidCallbacks::create(successCallback.release(), errorCallback.release(), 0);
+        OwnPtr<AsyncFileSystemCallbacks> fileSystemCallbacks = VoidCallbacks::create(successCallback.release(), errorCallback.release(), nullptr);
         LocalFileSystem::from(*executionContext)->deleteFileSystem(executionContext, type, fileSystemCallbacks.release());
     } else {
         OwnPtr<EntryCallback> successCallback = CallbackDispatcherFactory<EntryCallback>::create(this, &DeleteEntryRequest::didGetEntry);