[Not for review] record detailed time breakdown of SW related requests.

content/public/common/resource_response_info.h

Index: content/public/common/resource_response_info.h
diff --git a/content/public/common/resource_response_info.h b/content/public/common/resource_response_info.h
index 386ab96922217ac890decefd77e13a455e382eef..6f98ea683678a11801593e0c838d4994ad7dc44d 100644
--- a/content/public/common/resource_response_info.h
+++ b/content/public/common/resource_response_info.h
@@ -41,6 +41,9 @@ struct CONTENT_EXPORT ResourceResponseInfo {
   // responses, this time could be "far" in the past.
   base::Time response_time;
 
+  // TimeTicks::Now() when the browser sent the response to the renderer.
+  base::TimeTicks response_start;
+
   // The response headers or NULL if the URL type does not support headers.
   scoped_refptr<net::HttpResponseHeaders> headers;