Adding instrumentation to locate the source of jankiness.

google_apis/gcm/base/socket_stream.cc

 // Copyright 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 "google_apis/gcm/base/socket_stream.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/profiler/scoped_profile.h"
 #include "net/base/io_buffer.h"
 #include "net/socket/stream_socket.h"
 
 namespace gcm {
 
 namespace {
 
 // TODO(zea): consider having dynamically-sized buffers if this becomes too
 // expensive.
 const uint32 kDefaultBufferSize = 8*1024;
@@ skipping 136 matching lines @@
 
   DCHECK_EQ(last_error_, net::OK);
   if (read_buffer_->BytesConsumed() == next_pos_)
     return EMPTY;
 
   return READY;
 }
 
 void SocketInputStream::RefreshCompletionCallback(
     const base::Closure& callback, int result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/418183 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "418183 DoReadCallback => SocketInputStream::RefreshCompletionC..."));
+
   // If an error occurred before the completion callback could complete, ignore
   // the result.
   if (GetState() == CLOSED)
     return;
 
   // Result == 0 implies EOF, which is treated as an error.
   if (result == 0)
     result = net::ERR_CONNECTION_CLOSED;
 
   DCHECK_NE(result, net::ERR_IO_PENDING);
@@ skipping 153 matching lines @@
   }
 
   DVLOG(1) << "Socket flush complete.";
   write_buffer_->SetOffset(0);
   next_pos_ = 0;
   if (!callback.is_null())
     callback.Run();
 }
 
 }  // namespace gcm