Break two classes defined in json_value_serializer.cc, .h into separate files.

base/json/json_string_value_serializer.cc

Index: base/json/json_string_value_serializer.cc
===================================================================
--- base/json/json_string_value_serializer.cc	(revision 0)
+++ base/json/json_string_value_serializer.cc	(revision 0)
@@ -0,0 +1,45 @@
+// 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 "base/json/json_string_value_serializer.h"
+
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "base/logging.h"
+
+JSONStringValueSerializer::~JSONStringValueSerializer() {}
+
+bool JSONStringValueSerializer::Serialize(const Value& root) {
+  return SerializeInternal(root, false);
+}
+
+bool JSONStringValueSerializer::SerializeAndOmitBinaryValues(
+    const Value& root) {
+  return SerializeInternal(root, true);
+}
+
+bool JSONStringValueSerializer::SerializeInternal(const Value& root,
+                                                  bool omit_binary_values) {
+  if (!json_string_ || initialized_with_const_string_)
+    return false;
+
+  base::JSONWriter::WriteWithOptions(
+      &root,
+      pretty_print_,
+      omit_binary_values ? base::JSONWriter::OPTIONS_OMIT_BINARY_VALUES : 0,
+      json_string_);
+  return true;
+}
+
+Value* JSONStringValueSerializer::Deserialize(int* error_code,
+                                              std::string* error_str) {
+  if (!json_string_)
+    return NULL;
+
+  return base::JSONReader::ReadAndReturnError(*json_string_,
+                                              allow_trailing_comma_,
+                                              error_code,
+                                              error_str);
+}
+