Instrumenting read callbacks to find jank in TCPSocketWin::Core::ReadDelegate::OnObjectSignaled.

See the bug.

I was told that one of the pieces of code that could cause jank is the callback invoked in IO thread once the read on a socket is complete. I'm not familiar with the code, and I instrumented places that look relevant; feel free to suggest adding or removing the instrumentation.

BUG=418183
TBR=asanka@chromium.org

Review URL: https://codereview.chromium.org/637733002

Cr-Commit-Position: refs/heads/master@{#299176}

net/socket/ssl_client_socket_nss.cc

@@ -71,6 +71,7 @@
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/histogram.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
@@ -2213,6 +2214,10 @@ void SSLClientSocketNSS::Core::DoReadCallback(int rv) {
   PostOrRunCallback(
       FROM_HERE,
       base::Bind(&Core::DidNSSRead, this, rv));
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "SSLClientSocketNSS::Core::DoReadCallback"));
   PostOrRunCallback(
       FROM_HERE,
       base::Bind(base::ResetAndReturn(&user_read_callback_), rv));

net/socket/tcp_client_socket.cc

@@ -6,6 +6,7 @@
 
 #include "base/callback_helpers.h"
 #include "base/logging.h"
+#include "base/profiler/scoped_profile.h"
 #include "net/base/io_buffer.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/net_errors.h"
@@ -306,6 +307,10 @@ void TCPClientSocket::DidCompleteReadWrite(const CompletionCallback& callback,
   if (result > 0)
     use_history_.set_was_used_to_convey_data();
 
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "TCPClientSocket::DidCompleteReadWrite"));
   callback.Run(result);
 }
 

net/socket/tcp_socket_win.cc

@@ -1035,6 +1035,9 @@ void TCPSocketWin::DidSignalRead() {
   core_->read_buffer_length_ = 0;
 
   DCHECK_NE(rv, ERR_IO_PENDING);
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("TCPSocketWin::DidSignalRead"));
   base::ResetAndReturn(&read_callback_).Run(rv);
 }