Add DevToolsAgent::{enable,disable}Tracing

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 143 matching lines @@
   base::subtle::NoBarrier_Store(&event_callback_,
                                 reinterpret_cast<base::subtle::AtomicWord>(cb));
   if (!!cb) {
     trace_log->SetEventCallbackEnabled(base::debug::CategoryFilter(
         category_filter.utf8()), TraceEventCallbackWrapper);
   } else {
     trace_log->SetEventCallbackDisabled();
   }
 }
 
+void DevToolsAgent::enableTracing(const WebString& category_filter) {
+  TraceLog* trace_log = TraceLog::GetInstance();
+  trace_log->SetEnabled(base::debug::CategoryFilter(category_filter.utf8()),
+                        TraceLog::RECORDING_MODE,
+                        TraceLog::RECORD_UNTIL_FULL);

[pfeldman, 2014/04/21 17:50:52]

nit: do you want to pass this as a parameter?

+}
+
+void DevToolsAgent::disableTracing() {
+  TraceLog::GetInstance()->SetDisabled();
+}
+
 // static
 void DevToolsAgent::TraceEventCallbackWrapper(
     base::TimeTicks timestamp,
     char phase,
     const unsigned char* category_group_enabled,
     const char* name,
     unsigned long long id,
     int num_args,
     const char* const arg_names[],
     const unsigned char arg_types[],
@@ skipping 196 matching lines @@
   if (!web_view)
     return NULL;
   return web_view->devToolsAgent();
 }
 
 bool DevToolsAgent::IsAttached() {
   return is_attached_;
 }
 
 }  // namespace content