Print creator's call-stack on URLRequestContextGetter leak in Debug.

net/url_request/url_request_context_getter.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_request_context_getter.h"
 
 #include "base/debug/leak_annotations.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "net/url_request/url_request_context.h"
@@ skipping 22 matching lines @@
       GetNetworkTaskRunner();
   DCHECK(network_task_runner.get());
   if (network_task_runner.get()) {
     if (network_task_runner->BelongsToCurrentThread()) {
       delete this;
     } else {
       if (!network_task_runner->DeleteSoon(FROM_HERE, this)) {
         // Can't force-delete the object here, because some derived classes
         // can only be deleted on the owning thread, so just emit a warning to
         // aid in debugging.
+#if !defined(NDEBUG)

[Ryan Sleevi, 2017/02/22 19:45:57]

Did you mean to remove this logging for !NDEBUG builds?

[Wez, 2017/02/22 22:18:42]

This is already a DLOG(), so compiles to a void stream in NDEBUG builds. I
think.

/me runs off to check.

Yup, that is at least what DLOG is documented as doing.

         DLOG(WARNING) << "URLRequestContextGetter leaking due to no owning"
-                      << " thread.";
+                      << " thread. Created at: " << created_at.ToString();
+#endif  // !defined(NDEBUG)
         // Let LSan know we know this is a leak. https://crbug.com/594130
         ANNOTATE_LEAKING_OBJECT_PTR(this);
       }
     }
   }
   // If no IO task runner was available, we will just leak memory.
   // This is also true if the IO thread is gone.
 }
 
 void URLRequestContextGetter::NotifyContextShuttingDown() {
@@ skipping 18 matching lines @@
   return context_;
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 TrivialURLRequestContextGetter::GetNetworkTaskRunner() const {
   return main_task_runner_;
 }
 
 
 }  // namespace net