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

chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc

Index: chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
diff --git a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
index 67a9cc32c7e7b314e80857342dacafc8d4a02d5e..d18b3bb675ab8346896de13b0622c9052a330e06 100644
--- a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
+++ b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
@@ -89,12 +89,12 @@ bool ExtractsAppIdFromInput(const std::string& input,
     return false;
   }
 
-  const std::string path = webstore_url.path();
+  const base::StringPiece path = webstore_url.path();
   const size_t last_slash = path.rfind('/');
   if (last_slash == std::string::npos)
     return false;
 
-  const std::string candidate_id = path.substr(last_slash + 1);
+  const std::string candidate_id = path.substr(last_slash + 1).as_string();
   if (!crx_file::id_util::IdIsValid(candidate_id))
     return false;