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

chrome/browser/profiles/profile_avatar_icon_util.cc

 // Copyright 2014 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/profiles/profile_avatar_icon_util.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/files/file_util.h"
@@ skipping 496 matching lines @@
 
 bool GetImageURLWithThumbnailSize(
     const GURL& old_url, int size, GURL* new_url) {
   DCHECK(new_url);
   std::vector<std::string> components = base::SplitString(
       old_url.path(), std::string(1, kURLPathSeparator),
       base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
   if (components.empty())
     return false;
 
-  const std::string& old_path = old_url.path();
+  const base::StringPiece& old_path = old_url.path();
   std::string default_size_component(
       base::StringPrintf(kThumbnailSizeFormat, kDefaultThumbnailSize));
   std::string new_size_component(
       base::StringPrintf(kThumbnailSizeFormat, size));
 
   size_t pos = old_path.find(default_size_component);
   size_t end = std::string::npos;
   if (pos != std::string::npos) {
     // The default size is already specified in the URL so it needs to be
     // replaced with the new size.
     end = pos + default_size_component.size();
   } else {
     // The default size is not in the URL so try to insert it before the last
     // component.
     const std::string& file_name = old_url.ExtractFileName();
     if (!file_name.empty()) {
       pos = old_path.find(file_name);
       end = pos - 1;
     }
   }
 
   if (pos != std::string::npos) {
-    std::string new_path = old_path.substr(0, pos) + new_size_component +
-                           old_path.substr(end);
+    std::string new_path = old_path.substr(0, pos).as_string() +
+                           new_size_component +
+                           old_path.substr(end).as_string();
     GURL::Replacements replacement;
     replacement.SetPathStr(new_path.c_str());
     *new_url = old_url.ReplaceComponents(replacement);
     return new_url->is_valid();
   }
 
   // We can't set the image size, just use the default size.
   *new_url = old_url;
   return true;
 }
@@ skipping 11 matching lines @@
     avatar_info->SetString(
         "label", l10n_util::GetStringUTF16(
                      profiles::GetDefaultAvatarLabelResourceIDAtIndex(i)));
 
     avatars->Append(std::move(avatar_info));
   }
   return avatars;
 }
 
 }  // namespace profiles