Modify instrumentation for various jank bugs, mostly removing outdated sites.

net/url_request/url_fetcher_core.cc

Index: net/url_request/url_fetcher_core.cc
diff --git a/net/url_request/url_fetcher_core.cc b/net/url_request/url_fetcher_core.cc
index 8bc81dfce43ccc53d34c50afa747e701a99c8396..19ea48a777dc7f3e37576e9301220a41b4cf77e7 100644
--- a/net/url_request/url_fetcher_core.cc
+++ b/net/url_request/url_fetcher_core.cc
@@ -553,10 +553,6 @@ void URLFetcherCore::StartOnIOThread() {
 }
 
 void URLFetcherCore::StartURLRequest() {
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
-  tracked_objects::ScopedTracker tracking_profile1(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "456327 URLFetcherCore::StartURLRequest1"));
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
   if (was_cancelled_) {
@@ -575,10 +571,6 @@ void URLFetcherCore::StartURLRequest() {
   request_->set_stack_trace(stack_trace_);
   int flags = request_->load_flags() | load_flags_;
 
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
-  tracked_objects::ScopedTracker tracking_profile2(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "456327 URLFetcherCore::StartURLRequest2"));
   if (is_chunked_upload_)
     request_->EnableChunkedUpload();
   request_->SetLoadFlags(flags);
@@ -591,10 +583,6 @@ void URLFetcherCore::StartURLRequest() {
                           url_request_create_data_callback_.Run());
   }
 
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
-  tracked_objects::ScopedTracker tracking_profile3(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "456327 URLFetcherCore::StartURLRequest3"));
   switch (request_type_) {
     case URLFetcher::GET:
       break;
@@ -657,10 +645,6 @@ void URLFetcherCore::StartURLRequest() {
       NOTREACHED();
   }
 
-  // TODO(pkasting): Remove ScopedTracker below once crbug.com/456327 is fixed.
-  tracked_objects::ScopedTracker tracking_profile4(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "456327 URLFetcherCore::StartURLRequest4"));
   if (!extra_request_headers_.IsEmpty())
     request_->SetExtraRequestHeaders(extra_request_headers_);