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

components/plugins/renderer/mobile_youtube_plugin.cc

Index: components/plugins/renderer/mobile_youtube_plugin.cc
diff --git a/components/plugins/renderer/mobile_youtube_plugin.cc b/components/plugins/renderer/mobile_youtube_plugin.cc
index 455640b0fbc07b849cb2638b8751cd698a4bb162..d98b74ddf38b2c20540a028b7f9be320e93502cb 100644
--- a/components/plugins/renderer/mobile_youtube_plugin.cc
+++ b/components/plugins/renderer/mobile_youtube_plugin.cc
@@ -28,13 +28,13 @@ namespace {
 
 std::string GetYoutubeVideoId(const blink::WebPluginParams& params) {
   GURL url(params.url);
-  std::string video_id = url.path().substr(strlen(kSlashVSlash));
+  base::StringPiece video_id = url.path().substr(strlen(kSlashVSlash));
 
   // Extract just the video id
   size_t video_id_end = video_id.find('&');
   if (video_id_end != std::string::npos)
     video_id = video_id.substr(0, video_id_end);
-  return video_id;
+  return video_id.as_string();
 }
 
 std::string HtmlData(const blink::WebPluginParams& params,
@@ -44,7 +44,7 @@ std::string HtmlData(const blink::WebPluginParams& params,
   return webui::GetI18nTemplateHtml(template_html, &values);
 }
 
-bool IsValidYouTubeVideo(const std::string& path) {
+bool IsValidYouTubeVideo(const base::StringPiece& path) {
   unsigned len = strlen(kSlashVSlash);
 
   // check for more than just /v/ or /e/.