Adding instrumentation to locate the source of jankiness.

content/browser/appcache/view_appcache_internals_job.cc

Index: content/browser/appcache/view_appcache_internals_job.cc
diff --git a/content/browser/appcache/view_appcache_internals_job.cc b/content/browser/appcache/view_appcache_internals_job.cc
index acf989a8cf2efbffdb450dcb6e5ed01f86c4bf76..6b37562e9075751b381c7f0d488f122605f7f294 100644
--- a/content/browser/appcache/view_appcache_internals_job.cc
+++ b/content/browser/appcache/view_appcache_internals_job.cc
@@ -13,6 +13,7 @@
 #include "base/i18n/time_formatting.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -359,6 +360,10 @@ class MainPageJob : public BaseInternalsJob {
                       std::string* charset,
                       std::string* out,
                       const net::CompletionCallback& callback) const override {
+    // TODO(vadimt): Remove ScopedProfile below once crbug.com/422489 is fixed.
+    tracked_objects::ScopedProfile tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION("422489 MainPageJob::GetData"));
+
     mime_type->assign("text/html");
     charset->assign("UTF-8");
 
@@ -481,6 +486,10 @@ class ViewAppCacheJob : public BaseInternalsJob,
                       std::string* charset,
                       std::string* out,
                       const net::CompletionCallback& callback) const override {
+    // TODO(vadimt): Remove ScopedProfile below once crbug.com/422489 is fixed.
+    tracked_objects::ScopedProfile tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION("422489 ViewAppCacheJob::GetData"));
+
     mime_type->assign("text/html");
     charset->assign("UTF-8");
     out->clear();
@@ -557,6 +566,10 @@ class ViewEntryJob : public BaseInternalsJob,
                       std::string* charset,
                       std::string* out,
                       const net::CompletionCallback& callback) const override {
+    // TODO(vadimt): Remove ScopedProfile below once crbug.com/422489 is fixed.
+    tracked_objects::ScopedProfile tracking_profile(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION("422489 ViewEntryJob::GetData"));
+
     mime_type->assign("text/html");
     charset->assign("UTF-8");
     out->clear();