[fsp] Add support for aborting running operations.

chrome/browser/chromeos/file_system_provider/fileapi/file_stream_writer_unittest.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_writer.h"
 
 #include <string>
 #include <vector>
 
 #include "base/files/file.h"
@@ skipping 147 matching lines @@
         base::FilePath::FromUTF8Unsafe(kFakeFilePath), &entry));
 
     // The testing text is written twice.
     const std::string expected_contents =
         std::string(kTextToWrite) + kTextToWrite;
     EXPECT_EQ(expected_contents,
               entry.contents.substr(0, expected_contents.size()));
   }
 }
 
+TEST_F(FileSystemProviderFileStreamWriter, Cancel) {
+  std::vector<int> write_log;
+
+  const int64 initial_offset = 0;
+  FileStreamWriter writer(file_url_, initial_offset);
+  scoped_refptr<net::IOBuffer> io_buffer(new net::StringIOBuffer(kTextToWrite));
+
+  const int write_result = writer.Write(io_buffer.get(),
+                                        sizeof(kTextToWrite) - 1,
+                                        base::Bind(&LogValue, &write_log));
+  EXPECT_EQ(net::ERR_IO_PENDING, write_result);
+
+  std::vector<int> cancel_log;
+  const int cancel_result = writer.Cancel(base::Bind(&LogValue, &cancel_log));
+  EXPECT_EQ(net::ERR_IO_PENDING, cancel_result);
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_EQ(0u, write_log.size());
+  ASSERT_EQ(1u, cancel_log.size());
+  EXPECT_EQ(net::OK, cancel_log[0]);
+}
+
 TEST_F(FileSystemProviderFileStreamWriter, Write_WrongFile) {
   std::vector<int> write_log;
 
   const int64 initial_offset = 0;
   FileStreamWriter writer(wrong_file_url_, initial_offset);
   scoped_refptr<net::IOBuffer> io_buffer(new net::StringIOBuffer(kTextToWrite));
 
   const int result = writer.Write(io_buffer.get(),
                                   sizeof(kTextToWrite) - 1,
                                   base::Bind(&LogValue, &write_log));
@@ skipping 28 matching lines @@
 
   FakeEntry entry_after;
   ASSERT_TRUE(provided_file_system_->GetEntry(
       base::FilePath::FromUTF8Unsafe(kFakeFilePath), &entry_after));
   const std::string expected_contents = entry_before.contents + kTextToWrite;
   EXPECT_EQ(expected_contents, entry_after.contents);
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos