net: Move data reading functionalities from UploadElement to UploadElementReader

net/base/upload_element_reader.cc

Index: net/base/upload_element_reader.cc
diff --git a/net/base/upload_element_reader.cc b/net/base/upload_element_reader.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bb5cd85900c4418d5eedc61d3b623af91aa2b706
--- /dev/null
+++ b/net/base/upload_element_reader.cc
@@ -0,0 +1,38 @@
+// 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 "net/base/upload_element_reader.h"
+
+#include "base/logging.h"
+#include "net/base/upload_bytes_element_reader.h"
+#include "net/base/upload_element.h"
+#include "net/base/upload_file_element_reader.h"
+
+namespace net {
+
+// static
+UploadElementReader* UploadElementReader::Create(const UploadElement& element) {
+  UploadElementReader* reader = NULL;
+  switch (element.type()) {
+    case UploadElement::TYPE_BYTES:
+      reader = new UploadBytesElementReader(element.bytes(),
+                                            element.bytes_length());
+      break;
+    case UploadElement::TYPE_FILE:
+      reader = new UploadFileElementReader(
+          element.file_path(),
+          element.file_range_offset(),
+          element.file_range_length(),
+          element.expected_file_modification_time());
+      break;
+  }
+  DCHECK(reader);
+  return reader;
+}
+
+bool UploadElementReader::IsInMemory() const {
+  return false;
+}
+
+}  // namespace net