[tracing] Add support for profiling trace events

base/trace_event/blame_context.cc

 // Copyright 2016 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/trace_event/blame_context.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 
@@ skipping 37 matching lines @@
 void BlameContext::Leave() {
   DCHECK(WasInitialized());
   TRACE_EVENT_API_ADD_TRACE_EVENT(TRACE_EVENT_PHASE_LEAVE_CONTEXT,
                                   category_group_enabled_, name_, scope_, id_,
                                   0 /* num_args */, nullptr, nullptr, nullptr,
                                   nullptr, TRACE_EVENT_FLAG_HAS_ID);
 }
 
 void BlameContext::TakeSnapshot() {
   DCHECK(WasInitialized());
-  if (!*category_group_enabled_)
+  if (!(*category_group_enabled_ & TraceLog::ENABLED_FOR_NON_PROFILING_MODE))
     return;
   scoped_ptr<trace_event::TracedValue> snapshot(new trace_event::TracedValue);
   AsValueInto(snapshot.get());
   static const char* kArgName = "snapshot";
   const int kNumArgs = 1;
   unsigned char arg_types[1] = {TRACE_VALUE_TYPE_CONVERTABLE};
   scoped_ptr<trace_event::ConvertableToTraceFormat> arg_values[1] = {
       std::move(snapshot)};
   TRACE_EVENT_API_ADD_TRACE_EVENT(TRACE_EVENT_PHASE_SNAPSHOT_OBJECT,
                                   category_group_enabled_, type_, scope_, id_,
@@ skipping 27 matching lines @@
   trace_event::TraceLog::GetInstance()->AddEnabledStateObserver(this);
   TakeSnapshot();
 }
 
 bool BlameContext::WasInitialized() const {
   return category_group_enabled_ != nullptr;
 }
 
 }  // namespace trace_event
 }  // namespace base