Record UMA statistics for file_stream operations.

content/browser/download/base_file.cc

 // Copyright (c) 2011 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 "content/browser/download/base_file.h"
 
 #include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/stringprintf.h"
@@ skipping 180 matching lines @@
     : full_path_(full_path),
       source_url_(source_url),
       referrer_url_(referrer_url),
       file_stream_(file_stream),
       bytes_so_far_(received_bytes),
       power_save_blocker_(true),
       calculate_hash_(false),
       detached_(false) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   memset(sha256_hash_, 0, sizeof(sha256_hash_));
+  if (file_stream_.get())
+    file_stream_->EnableErrorStatistics();
 }
 
 BaseFile::~BaseFile() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (detached_)
     Close();
   else
     Cancel();  // Will delete the file.
 }
 
@@ skipping 170 matching lines @@
 }
 
 net::Error BaseFile::Open() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK(!detached_);
   DCHECK(!full_path_.empty());
 
   // Create a new file stream if it is not provided.
   if (!file_stream_.get()) {
     CreateFileStream();
+    file_stream_->EnableErrorStatistics();
     int open_result = file_stream_->Open(
         full_path_,
         base::PLATFORM_FILE_OPEN_ALWAYS | base::PLATFORM_FILE_WRITE);
     if (open_result != net::OK) {
       file_stream_.reset();
       return LOG_ERROR("Open", open_result);
     }
 
     // We may be re-opening the file after rename. Always make sure we're
     // writing at the end of the file.
@@ skipping 25 matching lines @@
 
 std::string BaseFile::DebugString() const {
   return base::StringPrintf("{ source_url_ = \"%s\""
                             " full_path_ = \"%" PRFilePath "\""
                             " bytes_so_far_ = %" PRId64 " detached_ = %c }",
                             source_url_.spec().c_str(),
                             full_path_.value().c_str(),
                             bytes_so_far_,
                             detached_ ? 'T' : 'F');
 }