Write file:// tests for BufferedDataSource and fix some bugs as a result.

webkit/media/test_response_generator.cc

 // Copyright (c) 2012 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 "webkit/media/test_response_generator.h"
 
 #include "base/format_macros.h"
 #include "base/string_number_conversions.h"
 #include "base/stringprintf.h"
 #include "net/base/net_errors.h"
@@ skipping 67 matching lines @@
   }
   return response;
 }
 
 WebURLResponse TestResponseGenerator::Generate404() {
   WebURLResponse response(gurl_);
   response.setHTTPStatusCode(404);
   return response;
 }
 
+WebURLResponse TestResponseGenerator::GenerateFileResponse(
+    int64 first_byte_offset) {
+  WebURLResponse response(gurl_);
+  response.setHTTPStatusCode(0);
+
+  if (first_byte_offset >= 0) {
+    response.setExpectedContentLength(content_length_ - first_byte_offset);
+  } else {
+    response.setExpectedContentLength(-1);
+  }
+  return response;
+}
+
 }  // namespace webkit_media