Adding instrumentation to locate the source of jankiness.

net/url_request/url_request_data_job.cc

Index: net/url_request/url_request_data_job.cc
diff --git a/net/url_request/url_request_data_job.cc b/net/url_request/url_request_data_job.cc
index e0746467079836f42aff97cdbe2029b6e5669eb9..db4367fc19e8e543f3c05091163a07550b96a9c1 100644
--- a/net/url_request/url_request_data_job.cc
+++ b/net/url_request/url_request_data_job.cc
@@ -6,6 +6,7 @@
 
 #include "net/url_request/url_request_data_job.h"
 
+#include "base/profiler/scoped_profile.h"
 #include "net/base/data_url.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
@@ -52,6 +53,10 @@ int URLRequestDataJob::GetData(std::string* mime_type,
                                std::string* charset,
                                std::string* data,
                                const CompletionCallback& callback) const {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422489 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("422489 URLRequestDataJob::GetData"));
+
   // Check if data URL is valid. If not, don't bother to try to extract data.
   // Otherwise, parse the data from the data URL.
   const GURL& url = request_->url();