[WIP] make GURL::path() return a StringPiece

net/test/embedded_test_server/request_handler_util.cc

Index: net/test/embedded_test_server/request_handler_util.cc
diff --git a/net/test/embedded_test_server/request_handler_util.cc b/net/test/embedded_test_server/request_handler_util.cc
index 8982efb8c0a7645687855e8eff3117f6b3a8fe8a..aa7aabb9934e1127144eb2dbcd4210cafed48155 100644
--- a/net/test/embedded_test_server/request_handler_util.cc
+++ b/net/test/embedded_test_server/request_handler_util.cc
@@ -130,7 +130,7 @@ std::unique_ptr<HttpResponse> HandleFileRequest(
   // A proxy request will have an absolute path. Simulate the proxy by stripping
   // the scheme, host, and port.
   GURL request_url = request.GetURL();
-  std::string relative_path(request_url.path());
+  base::StringPiece relative_path(request_url.path());
 
   std::string post_prefix("/post/");
   if (base::StartsWith(relative_path, post_prefix,
@@ -167,7 +167,7 @@ std::unique_ptr<HttpResponse> HandleFileRequest(
 
   // Trim the first byte ('/').
   DCHECK(base::StartsWith(relative_path, "/", base::CompareCase::SENSITIVE));
-  std::string request_path = relative_path.substr(1);
+  base::StringPiece request_path = relative_path.substr(1);
   base::FilePath file_path(server_root.AppendASCII(request_path));
   std::string file_contents;
   if (!base::ReadFileToString(file_path, &file_contents)) {