[fsp] Add throttling for number of opened files.

chrome/browser/chromeos/file_system_provider/fileapi/file_stream_reader.cc

 // 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.
 
 #include "chrome/browser/chromeos/file_system_provider/fileapi/file_stream_reader.h"
 
 #include "base/debug/trace_event.h"
 #include "base/files/file.h"
 #include "base/memory/ref_counted.h"
+#include "chrome/browser/chromeos/file_system_provider/abort_callback.h"
 #include "chrome/browser/chromeos/file_system_provider/fileapi/provider_async_file_util.h"
 #include "chrome/browser/chromeos/file_system_provider/mount_path_util.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 
 using content::BrowserThread;
 
 namespace chromeos {
@@ skipping 114 matching lines @@
 
     if (abort_callback_.is_null()) {
       // No operation to be cancelled. At most a callback call, which will be
       // discarded.
       BrowserThread::PostTask(BrowserThread::IO,
                               FROM_HERE,
                               base::Bind(callback, base::File::FILE_OK));
       return;
     }
 
-    const ProvidedFileSystemInterface::AbortCallback abort_callback =
-        abort_callback_;
-    abort_callback_ = ProvidedFileSystemInterface::AbortCallback();
-    abort_callback.Run(base::Bind(
+    const AbortCallback last_abort_callback = abort_callback_;
+    abort_callback_ = AbortCallback();
+    last_abort_callback.Run(base::Bind(
         &OperationRunner::OnAbortCompletedOnUIThread, this, callback));
   }
 
  private:
   friend class base::RefCountedThreadSafe<OperationRunner>;
 
   virtual ~OperationRunner() {}
 
   // Remembers a file handle for further operations and forwards the result to
   // the IO thread.
@@ skipping 36 matching lines @@
 
   // Forwards a response of aborting an operation to the IO thread.
   void OnAbortCompletedOnUIThread(
       const storage::AsyncFileUtil::StatusCallback& callback,
       base::File::Error result) {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE, base::Bind(callback, result));
   }
 
-  ProvidedFileSystemInterface::AbortCallback abort_callback_;
+  AbortCallback abort_callback_;
   base::WeakPtr<ProvidedFileSystemInterface> file_system_;
   base::FilePath file_path_;
   int file_handle_;
 
   DISALLOW_COPY_AND_ASSIGN(OperationRunner);
 };
 
 FileStreamReader::FileStreamReader(storage::FileSystemContext* context,
                                    const storage::FileSystemURL& url,
                                    int64 initial_offset,
@@ skipping 272 matching lines @@
     callback.Run(net::ERR_UPLOAD_FILE_CHANGED);
     return;
   }
 
   DCHECK_EQ(base::File::FILE_OK, result);
   callback.Run(metadata->size);
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos