Move EmptyString, kWhitespace and the BOM to base.

net/url_request/url_request_unittest.cc

Index: net/url_request/url_request_unittest.cc
diff --git a/net/url_request/url_request_unittest.cc b/net/url_request/url_request_unittest.cc
index 3564b2adf43668231370ddc097458a9fa9088f45..327ffefe76d4a4725a58340c7d3c5fa2dcaf9ccd 100644
--- a/net/url_request/url_request_unittest.cc
+++ b/net/url_request/url_request_unittest.cc
@@ -5688,7 +5688,7 @@ TEST_F(URLRequestTestHTTP, InterceptPost307RedirectPost) {
 TEST_F(URLRequestTestHTTP, DefaultAcceptLanguage) {
   ASSERT_TRUE(test_server_.Start());
 
-  StaticHttpUserAgentSettings settings("en", EmptyString());
+  StaticHttpUserAgentSettings settings("en", std::string());
   TestNetworkDelegate network_delegate;  // Must outlive URLRequests.
   TestURLRequestContext context(true);
   context.set_network_delegate(&network_delegate);
@@ -5709,7 +5709,8 @@ TEST_F(URLRequestTestHTTP, DefaultAcceptLanguage) {
 TEST_F(URLRequestTestHTTP, EmptyAcceptLanguage) {
   ASSERT_TRUE(test_server_.Start());
 
-  StaticHttpUserAgentSettings settings(EmptyString(), EmptyString());
+  std::string empty_string;  // Avoid most vexing parse on line below.
+  StaticHttpUserAgentSettings settings(empty_string, empty_string);
   TestNetworkDelegate network_delegate;  // Must outlive URLRequests.
   TestURLRequestContext context(true);
   context.set_network_delegate(&network_delegate);