Call WatcherManager functions on the IO thread.

chrome/browser/chromeos/extensions/file_manager/private_api_file_system.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file provides file system related API functions.
 
 #ifndef CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
+#include <memory>
+#include <set>
 #include <string>
+#include <vector>
 
+#include "base/callback_forward.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_base.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "chrome/browser/extensions/chrome_extension_function_details.h"
 #include "components/drive/file_errors.h"
 #include "device/media_transfer_protocol/mtp_storage_info.pb.h"
 #include "extensions/browser/extension_function.h"
 #include "storage/browser/fileapi/file_system_url.h"
 
 namespace storage {
 class FileSystemContext;
 class FileSystemURL;
+class WatcherManager;
 }  // namespace storage
 
 namespace file_manager {
+class EventRouter;
 namespace util {
 struct EntryDefinition;
 typedef std::vector<EntryDefinition> EntryDefinitionList;
 }  // namespace util
 }  // namespace file_manager
 
 namespace drive {
 namespace util {
 class FileStreamMd5Digester;
 }  // namespace util
@@ skipping 35 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(FileManagerPrivateGrantAccessFunction);
 };
 
 // Base class for FileManagerPrivateInternalAddFileWatchFunction and
 // FileManagerPrivateInternalRemoveFileWatchFunction. Although it's called
 // "FileWatch",
 // the class and its sub classes are used only for watching changes in
 // directories.
 class FileWatchFunctionBase : public LoggedAsyncExtensionFunction {
  public:
+  using ResponseCallback = base::Callback<void(bool success)>;
+
   // Calls SendResponse() with |success| converted to base::Value.
   void Respond(bool success);
 
  protected:
   ~FileWatchFunctionBase() override {}
 
-  // Performs a file watch operation (ex. adds or removes a file watch).
-  virtual void PerformFileWatchOperation(
+  // Performs a file watch operation (ex. adds or removes a file watch) on
+  // the IO thread with storage::WatcherManager.
+  virtual void PerformFileWatchOperationOnIOThread(
       scoped_refptr<storage::FileSystemContext> file_system_context,
+      storage::WatcherManager* watcher_manager,
       const storage::FileSystemURL& file_system_url,
-      const std::string& extension_id) = 0;
+      base::WeakPtr<file_manager::EventRouter> event_router) = 0;
+
+  // Performs a file watch operation (ex. adds or removes a file watch) on
+  // the UI thread with file_manager::EventRouter. This is a fallback operation
+  // called only when WatcherManager is unavailable.
+  virtual void PerformFallbackFileWatchOperationOnUIThread(
+      const storage::FileSystemURL& file_system_url,
+      base::WeakPtr<file_manager::EventRouter> event_router) = 0;
 
   // AsyncExtensionFunction overrides.
   bool RunAsync() override;
+
+ private:
+  void RunAsyncOnIOThread(
+      scoped_refptr<storage::FileSystemContext> file_system_context,
+      const storage::FileSystemURL& file_system_url,
+      base::WeakPtr<file_manager::EventRouter> event_router);
 };
 
 // Implements the chrome.fileManagerPrivate.addFileWatch method.
 // Starts watching changes in directories.
 class FileManagerPrivateInternalAddFileWatchFunction
     : public FileWatchFunctionBase {
  public:
   DECLARE_EXTENSION_FUNCTION("fileManagerPrivateInternal.addFileWatch",
                              FILEMANAGERPRIVATEINTERNAL_ADDFILEWATCH)
 
  protected:
   ~FileManagerPrivateInternalAddFileWatchFunction() override {}
 
   // FileWatchFunctionBase override.
-  void PerformFileWatchOperation(
+  void PerformFileWatchOperationOnIOThread(
       scoped_refptr<storage::FileSystemContext> file_system_context,
+      storage::WatcherManager* watcher_manager,
       const storage::FileSystemURL& file_system_url,
-      const std::string& extension_id) override;
+      base::WeakPtr<file_manager::EventRouter> event_router) override;
+  void PerformFallbackFileWatchOperationOnUIThread(
+      const storage::FileSystemURL& file_system_url,
+      base::WeakPtr<file_manager::EventRouter> event_router) override;
 };
 
 
 // Implements the chrome.fileManagerPrivate.removeFileWatch method.
 // Stops watching changes in directories.
 class FileManagerPrivateInternalRemoveFileWatchFunction
     : public FileWatchFunctionBase {
  public:
   DECLARE_EXTENSION_FUNCTION("fileManagerPrivateInternal.removeFileWatch",
                              FILEMANAGERPRIVATEINTERNAL_REMOVEFILEWATCH)
 
  protected:
   ~FileManagerPrivateInternalRemoveFileWatchFunction() override {}
 
   // FileWatchFunctionBase override.
-  void PerformFileWatchOperation(
+  void PerformFileWatchOperationOnIOThread(
       scoped_refptr<storage::FileSystemContext> file_system_context,
+      storage::WatcherManager* watcher_manager,
       const storage::FileSystemURL& file_system_url,
-      const std::string& extension_id) override;
+      base::WeakPtr<file_manager::EventRouter> event_router) override;
+  void PerformFallbackFileWatchOperationOnUIThread(
+      const storage::FileSystemURL& file_system_url,
+      base::WeakPtr<file_manager::EventRouter> event_router) override;
 };
 
 // Implements the chrome.fileManagerPrivate.getSizeStats method.
 class FileManagerPrivateGetSizeStatsFunction
     : public LoggedAsyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("fileManagerPrivate.getSizeStats",
                              FILEMANAGERPRIVATE_GETSIZESTATS)
 
  protected:
@@ skipping 196 matching lines @@
 
   void OnDirectorySizeRetrieved(int64_t size);
 
   // AsyncExtensionFunction overrides
   bool RunAsync() override;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_