Adding instrumentation to locate the source of jankiness.

chrome/browser/net/chrome_network_delegate.cc

 // Copyright (c) 2012 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 "chrome/browser/net/chrome_network_delegate.h"
 
 #include <stdlib.h>
 
 #include <vector>
 
 #include "base/base_paths.h"
 #include "base/debug/alias.h"
 #include "base/debug/dump_without_crashing.h"
 #include "base/debug/stack_trace.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/user_metrics.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_member.h"
 #include "base/prefs/pref_service.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/cookie_settings.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
 #include "chrome/browser/net/chrome_extensions_network_delegate.h"
 #include "chrome/browser/net/client_hints.h"
 #include "chrome/browser/net/connect_interceptor.h"
 #include "chrome/browser/net/safe_search_util.h"
@@ skipping 489 matching lines @@
 }
 
 
 void ChromeNetworkDelegate::OnResponseStarted(net::URLRequest* request) {
   TRACE_EVENT_ASYNC_STEP_PAST0("net", "URLRequest", request, "ResponseStarted");
   extensions_delegate_->OnResponseStarted(request);
 }
 
 void ChromeNetworkDelegate::OnRawBytesRead(const net::URLRequest& request,
                                            int bytes_read) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "423948 ChromeNetworkDelegate::OnRawBytesRead"));
+
   TRACE_EVENT_ASYNC_STEP_PAST1("net", "URLRequest", &request, "DidRead",
                                "bytes_read", bytes_read);
 #if defined(ENABLE_TASK_MANAGER)
   // This is not completely accurate, but as a first approximation ignore
   // requests that are served from the cache. See bug 330931 for more info.
   if (!request.was_cached())
     TaskManager::GetInstance()->model()->NotifyBytesRead(request, bytes_read);
 #endif  // defined(ENABLE_TASK_MANAGER)
 }
 
@@ skipping 283 matching lines @@
   if (data_reduction_proxy_statistics_prefs_) {
     StoreAccumulatedContentLength(received_content_length,
                                   original_content_length,
                                   request_type,
                                   reinterpret_cast<Profile*>(profile_),
                                   data_reduction_proxy_statistics_prefs_);
   }
   received_content_length_ += received_content_length;
   original_content_length_ += original_content_length;
 }