Add support for persistent file access in apps.

chrome/browser/extensions/api/file_system/file_system_api.h

Index: chrome/browser/extensions/api/file_system/file_system_api.h
diff --git a/chrome/browser/extensions/api/file_system/file_system_api.h b/chrome/browser/extensions/api/file_system/file_system_api.h
index 0dad0c025d92e9ecfad31c502333abdc6307ddd8..194fba8d5c0715d2e9da471b9cab102b72ed88b8 100644
--- a/chrome/browser/extensions/api/file_system/file_system_api.h
+++ b/chrome/browser/extensions/api/file_system/file_system_api.h
@@ -42,7 +42,8 @@ class FileSystemEntryFunction : public AsyncExtensionFunction {
   // from FileSelected, or from CreateFileIfNecessary. It is called on the UI
   // thread.
   void RegisterFileSystemAndSendResponse(const base::FilePath& path,
-                                         EntryType entry_type);
+                                         EntryType entry_type,
+                                         const std::string& id);

[Matt Giuca, 2013/05/16 06:40:59]

Since you have had to make existing calls pass "" here, would it be nicer to add
an overload that does not take an id?

[Sam McNally, 2013/05/17 03:38:52]

Done.

 
   // called on the UI thread if there is a problem checking a writable file.
   void HandleWritableFileError();
@@ -115,6 +116,36 @@ class FileSystemChooseEntryFunction : public FileSystemEntryFunction {
   base::FilePath initial_path_;
 };
 
+class FileSystemRetainEntryFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileSystem.retainEntry", FILESYSTEM_RETAINENTRY)
+
+ protected:
+  virtual ~FileSystemRetainEntryFunction() {}
+  virtual bool RunImpl() OVERRIDE;
+
+ private:
+  bool AddFileEntry(const std::string& entry_id);

[Matt Giuca, 2013/05/16 06:40:59]

Document this. Be sure to mention that |entry_id| needs to be an Isolated FS.

[Sam McNally, 2013/05/17 03:38:52]

Done.

+};
+
+class FileSystemIsRestorableFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileSystem.isRestorable", FILESYSTEM_ISRESTORABLE)
+
+ protected:
+  virtual ~FileSystemIsRestorableFunction() {}
+  virtual bool RunImpl() OVERRIDE;
+};
+
+class FileSystemRestoreEntryFunction : public FileSystemEntryFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileSystem.restoreEntry", FILESYSTEM_RESTOREENTRY)
+
+ protected:
+  virtual ~FileSystemRestoreEntryFunction() {}
+  virtual bool RunImpl() OVERRIDE;
+};
+
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_FILE_SYSTEM_FILE_SYSTEM_API_H_