Independently enable recording and event callback

content/renderer/devtools/devtools_agent.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 "content/renderer/devtools/devtools_agent.h"
 
 #include <map>
 
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
@@ skipping 64 matching lines @@
       is_devtools_client_(false) {
   g_agent_for_routing_id.Get()[routing_id()] = this;
 
   render_view->webview()->setDevToolsAgentClient(this);
   render_view->webview()->devToolsAgent()->setProcessId(
       base::Process::Current().pid());
 }
 
 DevToolsAgent::~DevToolsAgent() {
   g_agent_for_routing_id.Get().erase(routing_id());
+  setTraceEventCallback(NULL);
 }
 
 // Called on the Renderer thread.
 bool DevToolsAgent::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(DevToolsAgent, message)
     IPC_MESSAGE_HANDLER(DevToolsAgentMsg_Attach, OnAttach)
     IPC_MESSAGE_HANDLER(DevToolsAgentMsg_Reattach, OnReattach)
     IPC_MESSAGE_HANDLER(DevToolsAgentMsg_Detach, OnDetach)
     IPC_MESSAGE_HANDLER(DevToolsAgentMsg_DispatchOnInspectorBackend,
@@ skipping 35 matching lines @@
 void DevToolsAgent::clearBrowserCache() {
   Send(new DevToolsHostMsg_ClearBrowserCache(routing_id()));
 }
 
 void DevToolsAgent::clearBrowserCookies() {
   Send(new DevToolsHostMsg_ClearBrowserCookies(routing_id()));
 }
 
 void DevToolsAgent::setTraceEventCallback(TraceEventCallback cb) {
   TraceLog* trace_log = TraceLog::GetInstance();
-  trace_log->SetEventCallback(cb ? TraceEventCallbackWrapper : 0);
   base::subtle::NoBarrier_Store(&event_callback_,
                                 reinterpret_cast<base::subtle::AtomicWord>(cb));
   if (!!cb) {
-    trace_log->SetEnabled(base::debug::CategoryFilter(
-        base::debug::CategoryFilter::kDefaultCategoryFilterString),
-        TraceLog::RECORD_UNTIL_FULL);
+    trace_log->SetEventCallbackEnabled(base::debug::CategoryFilter(""),

[caseq, 2013/11/19 18:32:29]

Why did we stop using the default filter here? I think we rather want to
eventually narrow down the category filter here, expanding it to include
categories disable by default may slow things down.

[dsinclair, 2013/11/19 18:39:11]

This won't enable disabled-by-default-. Those will only be enabled if you
explicitly put them into the category string. This will enable the Debug and
Test categories that are removed as part of the default category filter.

[Xianzhu, 2013/11/19 18:39:21]

Actually CategoryFilter("") will create a default filter. However I changed back
to the original code which seems clearer.

+                                       cb ? TraceEventCallbackWrapper : 0);
   } else {
-    trace_log->SetDisabled();
+    trace_log->SetEventCallbackDisabled();
   }
 }
 
 void DevToolsAgent::TraceEventCallbackWrapper(
     base::TimeTicks timestamp,
     char phase,
     const unsigned char* category_group_enabled,
     const char* name,
     unsigned long long id,
     int num_args,
@@ skipping 139 matching lines @@
   if (!web_view)
     return NULL;
   return web_view->devToolsAgent();
 }
 
 bool DevToolsAgent::IsAttached() {
   return is_attached_;
 }
 
 }  // namespace content