Refactor AppendToFile and WriteFileDescriptor

content/common/gpu/media/vaapi_h264_decoder_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 <string>
 
 // This has to be included first.
 // See http://code.google.com/p/googletest/issues/detail?id=371
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 231 matching lines @@
     const scoped_refptr<media::VideoFrame>& frame) {
   frame->HashFrameForTesting(&md5_context_);
 
   if (output_file_.empty())
     return true;
 
   for (size_t i = 0; i < media::VideoFrame::NumPlanes(frame->format()); i++) {
     int to_write = media::VideoFrame::PlaneAllocationSize(
         frame->format(), i, frame->coded_size());
     const char* buf = reinterpret_cast<const char*>(frame->data(i));
-    int written = base::AppendToFile(output_file_, buf, to_write);
-    if (written != to_write)
+    if (!base::AppendToFile(output_file_, buf, to_write))
       return false;
   }
   return true;
 }
 
 void VaapiH264DecoderLoop::OutputPicture(
     int32 input_id,
     const scoped_refptr<VASurface>& va_surface) {
   VLOG(1) << "OutputPicture: picture " << num_outputted_pictures_++;
 
@@ skipping 113 matching lines @@
       content::g_md5sum = it->second;
       continue;
     }
     if (it->first == "v" || it->first == "vmodule")
       continue;
     LOG(FATAL) << "Unexpected switch: " << it->first << ":" << it->second;
   }
 
   return RUN_ALL_TESTS();
 }