Add support for TraceEvent before the native library is loaded.

content/browser/tracing/tracing_controller_impl.cc

 // Copyright (c) 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 "content/browser/tracing/tracing_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/json/string_escape.h"
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 301 matching lines @@
 #if defined(OS_ANDROID)
   if (pending_get_categories_done_callback_.is_null())
     TraceLog::GetInstance()->AddClockSyncMetadataEvent();
 #endif
 
   // Count myself (local trace) in pending_disable_recording_ack_count_,
   // acked below.
   pending_disable_recording_ack_count_ = trace_message_filters_.size() + 1;
   pending_disable_recording_filters_ = trace_message_filters_;
 
+  if (!disable_recording_callback_.is_null())
+    disable_recording_callback_.Run(TraceLog::GetInstance());
+
 #if defined(OS_CHROMEOS) || defined(OS_WIN)
   if (is_system_tracing_) {
     // Disable system tracing.
     is_system_tracing_ = false;
     ++pending_disable_recording_ack_count_;
 
 #if defined(OS_CHROMEOS)
     scoped_refptr<base::TaskRunner> task_runner =
         BrowserThread::GetBlockingPool();
     chromeos::DBusThreadManager::Get()
@@ skipping 537 matching lines @@
   DCHECK(tracing_uis_.find(tracing_ui) == tracing_uis_.end());
   tracing_uis_.insert(tracing_ui);
 }
 
 void TracingControllerImpl::UnregisterTracingUI(TracingUI* tracing_ui) {
   std::set<TracingUI*>::iterator it = tracing_uis_.find(tracing_ui);
   DCHECK(it != tracing_uis_.end());
   tracing_uis_.erase(it);
 }
 
+void TracingControllerImpl::SetDisableRecordingCallback(
+    const DisableRecordingCallback& callback) {
+  disable_recording_callback_ = callback;
+}
+
 void TracingControllerImpl::OnMonitoringStateChanged(bool is_monitoring) {
   if (is_monitoring_ == is_monitoring)
     return;
 
   is_monitoring_ = is_monitoring;
 #if !defined(OS_ANDROID)
   for (std::set<TracingUI*>::iterator it = tracing_uis_.begin();
        it != tracing_uis_.end(); it++) {
     (*it)->OnMonitoringStateChanged(is_monitoring);
   }
 #endif
 }
 
 }  // namespace content