[fsp] Decouple file_service_provider::Service.

chrome/browser/chromeos/file_system_provider/request_manager.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_
 
 #include <map>
 #include <string>
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/file_system_provider/observer.h"
-#include "chrome/browser/chromeos/file_system_provider/provided_file_system.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
 
 namespace base {
 class DictionaryValue;
 }  // namespace base
 
 namespace chromeos {
 namespace file_system_provider {
 
-typedef base::Callback<void(scoped_ptr<base::DictionaryValue>, bool has_next)>
-    SuccessCallback;
+typedef base::Callback<void(scoped_ptr<base::DictionaryValue> result,
+                            bool has_next)> SuccessCallback;
 typedef base::Callback<void(base::File::Error)> ErrorCallback;
 
 // Manages requests between the service, async utils and the providing
 // extensions.
+// TODO(mtomasz): Create for each provided file system.
 class RequestManager : public Observer {
  public:
   RequestManager();
   virtual ~RequestManager();
 
   // Creates a request and returns its request id (greater than 0). Returns 0 in
   // case of an error (eg. too many requests). The passed callbacks can be NULL.
-  int CreateRequest(const ProvidedFileSystem& file_system,
+  int CreateRequest(const std::string& extension_id,

[hashimoto, 2014/04/11 06:01:50]

Perhaps I might have asked this previously, but just in case.
Why do we need to pass extension_id?
There can be multiple filesystems with the same file_system_id, but provided by
different extensions?

[mtomasz, 2014/04/11 07:11:56]

Basically, I wanted to avoid situation, when an malicious or incorrectly written
providing extension uses wront request id, and as a result accesses a request of
another extension. By passing an extension id, we can check, if the source
extension id matches the extension id used for the request.

[hashimoto, 2014/04/14 10:43:42]

Makes sense.

+                    int file_system_id,
                     const SuccessCallback& success_callback,
                     const ErrorCallback& error_callback);
 
   // Handles successful response for the |request_id|. If |has_next| is false,
   // then the request is disposed, after handling the |response|. On error,
   // returns false, and the request is disposed.
-  bool FulfillRequest(const ProvidedFileSystem& file_system,
+  bool FulfillRequest(const std::string& extension_id,
+                      int file_system_id,
                       int request_id,
                       scoped_ptr<base::DictionaryValue> response,
                       bool has_next);
 
   // Handles error response for the |request_id|. If handling the error fails,
   // returns false. Always disposes the request.
-  bool RejectRequest(const ProvidedFileSystem& file_system,
+  bool RejectRequest(const std::string& extension_id,
+                     int file_system_id,
                      int request_id,
                      base::File::Error error);
 
   // file_system_provider::Observer overrides.
-  virtual void OnProvidedFileSystemMount(const ProvidedFileSystem& file_system,
-                                         base::File::Error error) OVERRIDE;
+  virtual void OnProvidedFileSystemMount(
+      const ProvidedFileSystemInfo& file_system_info,
+      base::File::Error error) OVERRIDE;
   virtual void OnProvidedFileSystemUnmount(
-      const ProvidedFileSystem& file_system,
+      const ProvidedFileSystemInfo& file_system_info,
       base::File::Error error) OVERRIDE;
 
  private:
   struct Request {
     Request();
     ~Request();
 
-    // Provided file system handling the request.
-    ProvidedFileSystem file_system;
+    // Providing extension's ID.
+    std::string extension_id;
+
+    // Provided file system's ID.
+    int file_system_id;
 
     // Callback to be called on success.
     SuccessCallback success_callback;
 
     // Callback to be called on error.
     ErrorCallback error_callback;
   };
 
   typedef std::map<int, Request> RequestMap;
 
   RequestMap requests_;
   int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestManager);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_