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

chrome/browser/chromeos/login/signin/oauth2_browsertest.cc

Index: chrome/browser/chromeos/login/signin/oauth2_browsertest.cc
diff --git a/chrome/browser/chromeos/login/signin/oauth2_browsertest.cc b/chrome/browser/chromeos/login/signin/oauth2_browsertest.cc
index a90267e24de08052566bb3a6248d07937f8a01b6..ea67118e38f7735c602f016fb5945a30ce8b13f1 100644
--- a/chrome/browser/chromeos/login/signin/oauth2_browsertest.cc
+++ b/chrome/browser/chromeos/login/signin/oauth2_browsertest.cc
@@ -530,7 +530,7 @@ class FakeGoogle {
     // get a valid GURL in order to parse |request.relative_url|.
     GURL request_url = GURL("http://localhost").Resolve(request.relative_url);
     LOG(WARNING) << "Requesting page " << request.relative_url;
-    std::string request_path = request_url.path();
+    base::StringPiece request_path = request_url.path();
     std::unique_ptr<BasicHttpResponse> http_response(new BasicHttpResponse());
     if (request_path == kHelloPagePath) {  // Serving "google" page.
       start_event_.Signal();