Enable warning 4389 as an error on windows builds. This will make...

net/tools/dump_cache/cache_dumper.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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 "net/tools/dump_cache/cache_dumper.h"
 
 #include "net/base/io_buffer.h"
 #include "net/disk_cache/entry_impl.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_response_info.h"
@@ skipping 70 matching lines @@
 
   entry_url_ = key;
 
   FilePath directory = entry_path_.DirName();
   SafeCreateDirectory(directory.value());
 
   std::wstring file = entry_path_.value();
 #ifdef WIN32_LARGE_FILENAME_SUPPORT
   entry_ = CreateFileW(file.c_str(), GENERIC_WRITE|GENERIC_READ, 0, 0,
                        CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
+  if (entry_ == INVALID_HANDLE_VALUE) {
+    wprintf(L"CreateFileW (%s) failed: %d\n", file.c_str(), GetLastError());
+    return false;
+  }
   return entry_ != INVALID_HANDLE_VALUE;
 #else
   entry_ = file_util::OpenFile(entry_path_, "w+");
   return entry_ != NULL;
 #endif
 }
 
 // Utility Function to create a normalized header string from a
 // HttpResponseInfo.  The output will be formatted exactly
 // like so:
@@ skipping 75 matching lines @@
 
     data = headers.c_str();
     len = headers.size();
   } else if (index == 1) {  // Stream 1 is the data.
     data = buf->data();
     len = buf_len;
   }
 #ifdef WIN32_LARGE_FILENAME_SUPPORT
   DWORD bytes;
   DWORD rv = WriteFile(entry_, data, len, &bytes, 0);
-  return rv == TRUE && bytes == len;
+  return rv == TRUE && bytes == static_cast<DWORD>(len);
 #else
   int bytes = fwrite(data, 1, len, entry_);
   return bytes == len;
 #endif
 }
 
 void DiskDumper::CloseEntry(disk_cache::Entry* entry, base::Time last_used,
                           base::Time last_modified) {
 #ifdef WIN32_LARGE_FILENAME_SUPPORT
   CloseHandle(entry_);
 #else
   file_util::CloseFile(entry_);
 #endif
 }