New test infrastructure for producing verbose logs in failing tests.

base/win/event_trace_provider.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// 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 "base/win/event_trace_provider.h"
 #include <windows.h>
 #include <cguid.h>
 
 namespace base {
 namespace win {
 
@@ skipping 65 matching lines @@
 
 ULONG EtwTraceProvider::Register() {
   if (provider_name_ == GUID_NULL)
     return ERROR_INVALID_NAME;
 
   return ::RegisterTraceGuids(ControlCallback, this, &provider_name_,
       1, &obligatory_guid_registration_, NULL, NULL, &registration_handle_);
 }
 
 ULONG EtwTraceProvider::Unregister() {
+  // If a session is active, notify subclasses that it's going away.
+  if (session_handle_ != NULL)
+    DisableEvents();
+
   ULONG ret = ::UnregisterTraceGuids(registration_handle_);
 
-  // Make sure we don't log anything from here on.
-  enable_level_ = 0;
-  enable_flags_ = 0;
-  session_handle_ = NULL;
   registration_handle_ = NULL;
 
   return ret;
 }
 
 ULONG EtwTraceProvider::Log(const EtwEventClass& event_class,
     EtwEventType type, EtwEventLevel level, const char *message) {
   if (NULL == session_handle_ || enable_level_ < level)
     return ERROR_SUCCESS;  // No one listening.
 
@@ skipping 22 matching lines @@
 
 ULONG EtwTraceProvider::Log(EVENT_TRACE_HEADER* event) {
   if (enable_level_ < event->Class.Level)
     return ERROR_SUCCESS;
 
   return ::TraceEvent(session_handle_, event);
 }
 
 }  // namespace win
 }  // namespace base