Update from https://crrev.com/316786

net/url_request/url_fetcher_core.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 "net/url_request/url_fetcher_core.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 523 matching lines @@
   g_ignore_certificate_requests = ignored;
 }
 
 URLFetcherCore::~URLFetcherCore() {
   // |request_| should be NULL. If not, it's unsafe to delete it here since we
   // may not be on the IO thread.
   DCHECK(!request_.get());
 }
 
 void URLFetcherCore::StartOnIOThread() {
+  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "456327 URLFetcherCore::StartOnIOThread"));
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
   if (!response_writer_)
     response_writer_.reset(new URLFetcherStringWriter);
 
   const int result = response_writer_->Initialize(
       base::Bind(&URLFetcherCore::DidInitializeWriter, this));
   if (result != ERR_IO_PENDING)
     DidInitializeWriter(result);
 }
 
 void URLFetcherCore::StartURLRequest() {
+  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "456327 URLFetcherCore::StartURLRequest"));
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
   if (was_cancelled_) {
     // Since StartURLRequest() is posted as a *delayed* task, it may
     // run after the URLFetcher was already stopped.
     return;
   }
 
   DCHECK(request_context_getter_.get());
   DCHECK(!request_.get());
@@ skipping 96 matching lines @@
 }
 
 void URLFetcherCore::StartURLRequestWhenAppropriate() {
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
   if (was_cancelled_)
     return;
 
   DCHECK(request_context_getter_.get());
 
-  int64 delay = INT64_C(0);
+  int64 delay = 0;
   if (!original_url_throttler_entry_.get()) {
+    // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is
+    // fixed.
+    tracked_objects::ScopedTracker tracking_profile1(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "456327 URLFetcherCore::StartURLRequestWhenAppropriate1"));
     URLRequestThrottlerManager* manager =
         request_context_getter_->GetURLRequestContext()->throttler_manager();
     if (manager) {
       original_url_throttler_entry_ =
           manager->RegisterRequestUrl(original_url_);
     }
   }
   if (original_url_throttler_entry_.get()) {
+    // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is
+    // fixed.
+    tracked_objects::ScopedTracker tracking_profile2(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "456327 URLFetcherCore::StartURLRequestWhenAppropriate2"));
     delay = original_url_throttler_entry_->ReserveSendingTimeForNextRequest(
         GetBackoffReleaseTime());
   }
 
-  if (delay == INT64_C(0)) {
+  if (delay == 0) {
     StartURLRequest();
   } else {
     base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE, base::Bind(&URLFetcherCore::StartURLRequest, this),
         base::TimeDelta::FromMilliseconds(delay));
   }
 }
 
 void URLFetcherCore::CancelURLRequest(int error) {
   DCHECK(network_task_runner_->BelongsToCurrentThread());
@@ skipping 274 matching lines @@
 }
 
 void URLFetcherCore::AssertHasNoUploadData() const {
   DCHECK(!upload_content_set_);
   DCHECK(upload_content_.empty());
   DCHECK(upload_file_path_.empty());
   DCHECK(upload_stream_factory_.is_null());
 }
 
 }  // namespace net