Remove unnecessary instrumentation for several jank bugs.

net/disk_cache/blockfile/in_flight_io.cc

Index: net/disk_cache/blockfile/in_flight_io.cc
diff --git a/net/disk_cache/blockfile/in_flight_io.cc b/net/disk_cache/blockfile/in_flight_io.cc
index cbfcd1729fce5dbecbc0b5dbc744b60147fafd83..9ada7c53a7cb0229df6cbed6741508a561fd8b16 100644
--- a/net/disk_cache/blockfile/in_flight_io.cc
+++ b/net/disk_cache/blockfile/in_flight_io.cc
@@ -7,7 +7,6 @@
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
-#include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
 #include "base/thread_task_runner_handle.h"
@@ -88,10 +87,6 @@ void InFlightIO::OnIOComplete(BackgroundIO* operation) {
 // Runs on the primary thread.
 void InFlightIO::InvokeCallback(BackgroundIO* operation, bool cancel_task) {
   {
-    // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
-    tracked_objects::ScopedTracker tracking_profile(
-        FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 InFlightIO::InvokeCallback"));
-
     // http://crbug.com/74623
     base::ThreadRestrictions::ScopedAllowWait allow_wait;
     operation->io_completed()->Wait();