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

chrome/browser/profiles/profile_avatar_icon_util.cc

Index: chrome/browser/profiles/profile_avatar_icon_util.cc
diff --git a/chrome/browser/profiles/profile_avatar_icon_util.cc b/chrome/browser/profiles/profile_avatar_icon_util.cc
index 146bd75a0882246e186aa4bc6a60d1bfa83fca39..ab7b83d23f91983c022499078b258d6fbd02f0eb 100644
--- a/chrome/browser/profiles/profile_avatar_icon_util.cc
+++ b/chrome/browser/profiles/profile_avatar_icon_util.cc
@@ -514,7 +514,7 @@ bool GetImageURLWithThumbnailSize(
   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(
@@ -537,8 +537,9 @@ bool GetImageURLWithThumbnailSize(
   }
 
   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);