[ew] Simplify the entry watcher logic.

content/public/test/test_file_system_backend.cc

Index: content/public/test/test_file_system_backend.cc
diff --git a/content/public/test/test_file_system_backend.cc b/content/public/test/test_file_system_backend.cc
index 1b9e0a54ff6076ba5cc60e31af855ae084aa2229..3c34714e04a27f9a9d65074c3c3d8fc86905ccbd 100644
--- a/content/public/test/test_file_system_backend.cc
+++ b/content/public/test/test_file_system_backend.cc
@@ -24,7 +24,6 @@
 #include "storage/browser/fileapi/native_file_util.h"
 #include "storage/browser/fileapi/quota/quota_reservation.h"
 #include "storage/browser/fileapi/sandbox_file_stream_writer.h"
-#include "storage/browser/fileapi/watcher_manager.h"
 #include "storage/browser/quota/quota_manager.h"
 #include "storage/common/fileapi/file_system_util.h"
 
@@ -56,101 +55,6 @@ class TestFileUtil : public storage::LocalFileUtil {
   base::FilePath base_path_;
 };
 
-// Stub implementation of storage::WatcherManager. Emits a fake notification
-// after a directory watcher is set successfully.
-class TestWatcherManager : public storage::WatcherManager {
- public:
-  TestWatcherManager() : weak_ptr_factory_(this) {}
-  ~TestWatcherManager() override {}
-
-  // storage::WatcherManager overrides.
-  void AddObserver(Observer* observer) override {
-    observers_.AddObserver(observer);
-  }
-
-  void RemoveObserver(Observer* observer) override {
-    observers_.RemoveObserver(observer);
-  }
-
-  bool HasObserver(Observer* observer) const override {
-    return observers_.HasObserver(observer);
-  }
-
-  void WatchDirectory(const storage::FileSystemURL& url,
-                      bool recursive,
-                      const StatusCallback& callback) override {
-    if (recursive) {
-      base::ThreadTaskRunnerHandle::Get()->PostTask(
-          FROM_HERE,
-          base::Bind(callback, base::File::FILE_ERROR_INVALID_OPERATION));
-      return;
-    }
-
-    const GURL gurl = url.ToGURL();
-    if (watched_urls_.find(gurl) != watched_urls_.end()) {
-      base::ThreadTaskRunnerHandle::Get()->PostTask(
-          FROM_HERE, base::Bind(callback, base::File::FILE_ERROR_EXISTS));
-      return;
-    }
-
-    watched_urls_.insert(gurl);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, base::File::FILE_OK));
-
-    // Send a fake changed notification.
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&TestWatcherManager::SendFakeChangeNotification,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   url));
-
-    // Send a fake removed notification.
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&TestWatcherManager::SendFakeRemoveNotification,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   url));
-  }
-
-  void UnwatchEntry(const storage::FileSystemURL& url,
-                    const StatusCallback& callback) override {
-    const GURL gurl = url.ToGURL();
-    if (watched_urls_.find(gurl) == watched_urls_.end()) {
-      base::ThreadTaskRunnerHandle::Get()->PostTask(
-          FROM_HERE, base::Bind(callback, base::File::FILE_ERROR_NOT_FOUND));
-      return;
-    }
-
-    watched_urls_.erase(gurl);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, base::File::FILE_OK));
-  }
-
- private:
-  // Sends a fake notification to each observer about a changed entry
-  // represented by |url|, as long as it is still being watched.
-  void SendFakeChangeNotification(const storage::FileSystemURL& url) {
-    if (watched_urls_.find(url.ToGURL()) == watched_urls_.end())
-      return;
-
-    FOR_EACH_OBSERVER(Observer, observers_, OnEntryChanged(url));
-  }
-
-  // Sends a fake notification to each observer about a removed entry
-  // represented by |url|, as long as it is still being watched.
-  void SendFakeRemoveNotification(const storage::FileSystemURL& url) {
-    if (watched_urls_.find(url.ToGURL()) == watched_urls_.end())
-      return;
-
-    FOR_EACH_OBSERVER(Observer, observers_, OnEntryRemoved(url));
-  }
-
-  ObserverList<Observer> observers_;
-  std::set<GURL> watched_urls_;
-
-  base::WeakPtrFactory<TestWatcherManager> weak_ptr_factory_;
-};
-
 }  // namespace
 
 // This only supports single origin.
@@ -214,7 +118,6 @@ TestFileSystemBackend::TestFileSystemBackend(
       task_runner_(task_runner),
       file_util_(
           new storage::AsyncFileUtilAdapter(new TestFileUtil(base_path))),
-      watcher_manager_(new TestWatcherManager()),
       quota_util_(new QuotaUtil),
       require_copy_or_move_validator_(false) {
   update_observers_ =
@@ -246,7 +149,7 @@ storage::AsyncFileUtil* TestFileSystemBackend::GetAsyncFileUtil(
 
 storage::WatcherManager* TestFileSystemBackend::GetWatcherManager(
     storage::FileSystemType type) {
-  return watcher_manager_.get();
+  return nullptr;
 }
 
 storage::CopyOrMoveFileValidatorFactory*
@@ -260,7 +163,7 @@ TestFileSystemBackend::GetCopyOrMoveFileValidatorFactory(
       *error_code = base::File::FILE_ERROR_SECURITY;
     return copy_or_move_file_validator_factory_.get();
   }
-  return NULL;
+  return nullptr;
 }
 
 void TestFileSystemBackend::InitializeCopyOrMoveFileValidatorFactory(
@@ -328,7 +231,7 @@ const storage::ChangeObserverList* TestFileSystemBackend::GetChangeObservers(
 
 const storage::AccessObserverList* TestFileSystemBackend::GetAccessObservers(
     storage::FileSystemType type) const {
-  return NULL;
+  return nullptr;
 }
 
 void TestFileSystemBackend::AddFileChangeObserver(