Remove unnecessary instrumentation for several jank bugs.

net/proxy/proxy_resolver_v8_tracing.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/proxy/proxy_resolver_v8_tracing.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/strings/stringprintf.h"
@@ skipping 704 matching lines @@
   }
 
   if (!blocking_dns_) {
     // The worker thread always blocks waiting to see if the result can be
     // serviced from cache before restarting.
     event_.Signal();
   }
 }
 
 void ProxyResolverV8Tracing::Job::OnDnsOperationComplete(int result) {
-  // TODO(vadimt): Remove ScopedTracker below once crbug.com/436634 is fixed.
-  tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "436634 ProxyResolverV8Tracing::Job::OnDnsOperationComplete"));
-
   CheckIsOnOriginThread();
 
   DCHECK(!cancelled_.IsSet());
   DCHECK(pending_dns_completed_synchronously_ == (pending_dns_ == NULL));
 
   SaveDnsToLocalCache(pending_dns_host_, pending_dns_op_, result,
                       pending_dns_addresses_);
   pending_dns_ = NULL;
 
   if (!parent_->on_load_state_changed_.is_null() &&
@@ skipping 294 matching lines @@
   DCHECK(!set_pac_script_job_.get());
   CHECK_EQ(0, num_outstanding_callbacks_);
 
   set_pac_script_job_ = new Job(this);
   set_pac_script_job_->StartSetPacScript(script_data, callback);
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net