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

chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h"
 
 #include "chrome/browser/chromeos/login/lock/screen_locker.h"
 #include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h"
 #include "chrome/common/url_constants.h"
 #include "net/base/escape.h"
@@ skipping 26 matching lines @@
     const std::string& path,
     const content::ResourceRequestInfo::WebContentsGetter& wc_getter,
     const content::URLDataSource::GotDataCallback& callback) {
   if (!icon_provider_) {
     callback.Run(GetDefaultIcon().As1xPNGBytes().get());
     return;
   }
 
   GURL url(chrome::kChromeUIScreenlockIconURL + path);
   std::string username = net::UnescapeURLComponent(
-      url.path().substr(1),
+      url.path().as_string().substr(1),
       net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS |
           net::UnescapeRule::PATH_SEPARATORS | net::UnescapeRule::SPACES);
 
   gfx::Image image = icon_provider_->GetIcon(username);
   if (image.IsEmpty()) {
     callback.Run(GetDefaultIcon().As1xPNGBytes().get());
     return;
   }
 
   callback.Run(image.As1xPNGBytes().get());
 }
 
 std::string ScreenlockIconSource::GetMimeType(const std::string&) const {
   return "image/png";
 }
 
 // static.
 std::string ScreenlockIconSource::GetIconURLForUser(
     const std::string& username) {
   return std::string(chrome::kChromeUIScreenlockIconURL) +
       net::EscapePath(username);
 }
 
 }  // namespace chromeos