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

chrome/browser/ui/webui/options/chromeos/user_image_source.cc

Index: chrome/browser/ui/webui/options/chromeos/user_image_source.cc
diff --git a/chrome/browser/ui/webui/options/chromeos/user_image_source.cc b/chrome/browser/ui/webui/options/chromeos/user_image_source.cc
index ae1a8719ccc20f9a3dc446d68c0fb3e762592a30..a38ecbe5dee0f294221be50a512d41d456729d23 100644
--- a/chrome/browser/ui/webui/options/chromeos/user_image_source.cc
+++ b/chrome/browser/ui/webui/options/chromeos/user_image_source.cc
@@ -27,7 +27,7 @@ namespace {
 void ParseRequest(const GURL& url, std::string* email) {
   DCHECK(url.is_valid());
   const std::string serialized_account_id = 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);
   AccountId account_id(EmptyAccountId());