Add support for directory access to the file system API.

apps/saved_files_service.h

Index: apps/saved_files_service.h
diff --git a/apps/saved_files_service.h b/apps/saved_files_service.h
index 25b96d7671af7530994f3eca9af854e7b314d1d1..4c86a0cd854d5d172c4bb598059a44776ac655a0 100644
--- a/apps/saved_files_service.h
+++ b/apps/saved_files_service.h
@@ -37,6 +37,7 @@ struct SavedFileEntry {
 
   SavedFileEntry(const std::string& id,
                  const base::FilePath& path,
+                 bool is_directory,
                  int sequence_number);
 
   // The opaque id of this file entry.
@@ -45,6 +46,9 @@ struct SavedFileEntry {
   // The path to a file entry that the app had permission to access.
   base::FilePath path;
 
+  // Whether or not the entry refers to a directory.
+  bool is_directory;
+
   // The sequence number in the LRU of the file entry. The value 0 indicates
   // that the entry is not in the LRU.
   int sequence_number;
@@ -65,7 +69,8 @@ class SavedFilesService : public BrowserContextKeyedService,
   // object construction are automatically registered.
   void RegisterFileEntry(const std::string& extension_id,
                          const std::string& id,
-                         const base::FilePath& file_path);
+                         const base::FilePath& file_path,
+                         bool is_directory);
 
   // If the file with |id| is not in the queue of files to be retained
   // permanently, adds the file to the back of the queue, evicting the least