Remove some naked |new| statements in favor of MakeUnique.

net/http/bidirectional_stream.cc

Index: net/http/bidirectional_stream.cc
diff --git a/net/http/bidirectional_stream.cc b/net/http/bidirectional_stream.cc
index c984b53eb1581704ee9eb63abb020e72fd4bb5ba..f76dee08a41d0978d4e35aba0c6df4b861944a38 100644
--- a/net/http/bidirectional_stream.cc
+++ b/net/http/bidirectional_stream.cc
@@ -39,7 +39,7 @@ namespace {
 std::unique_ptr<base::Value> NetLogHeadersCallback(
     const SpdyHeaderBlock* headers,
     NetLogCaptureMode capture_mode) {
-  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
+  auto dict = base::MakeUnique<base::DictionaryValue>();
   dict->Set("headers", ElideSpdyHeaderBlockForNetLog(*headers, capture_mode));
   return std::move(dict);
 }
@@ -48,7 +48,7 @@ std::unique_ptr<base::Value> NetLogCallback(const GURL* url,
                                             const std::string* method,
                                             const HttpRequestHeaders* headers,
                                             NetLogCaptureMode capture_mode) {
-  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
+  auto dict = base::MakeUnique<base::DictionaryValue>();
   dict->SetString("url", url->possibly_invalid_spec());
   dict->SetString("method", *method);
   std::string empty;