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

components/sync/engine_impl/attachments/attachment_uploader_impl.cc

Index: components/sync/engine_impl/attachments/attachment_uploader_impl.cc
diff --git a/components/sync/engine_impl/attachments/attachment_uploader_impl.cc b/components/sync/engine_impl/attachments/attachment_uploader_impl.cc
index 2e8ff0025b37829352b8aa144c4560beb5cab187..6c58d4cf5753b44f72f725f753479ddbd1d4494b 100644
--- a/components/sync/engine_impl/attachments/attachment_uploader_impl.cc
+++ b/components/sync/engine_impl/attachments/attachment_uploader_impl.cc
@@ -332,7 +332,7 @@ void AttachmentUploaderImpl::UploadAttachment(const Attachment& attachment,
 GURL AttachmentUploaderImpl::GetURLForAttachmentId(
     const GURL& sync_service_url,
     const AttachmentId& attachment_id) {
-  std::string path = sync_service_url.path();
+  std::string path = sync_service_url.path().as_string();
   if (path.empty() || *path.rbegin() != '/') {
     path += '/';
   }