Change sampler code events phase from instant to meta.

base/trace_event/memory_dump_manager.cc

 // Copyright 2015 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/memory_dump_manager.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 528 matching lines @@
   scoped_refptr<StackFrameDeduplicator> stack_frame_deduplicator = nullptr;
   scoped_refptr<TypeNameDeduplicator> type_name_deduplicator = nullptr;
 
   if (heap_profiling_enabled_) {
     // If heap profiling is enabled, the stack frame deduplicator and type name
     // deduplicator will be in use. Add a metadata events to write the frames
     // and type IDs.
     stack_frame_deduplicator = new StackFrameDeduplicator;
     type_name_deduplicator = new TypeNameDeduplicator;
     TRACE_EVENT_API_ADD_METADATA_EVENT(
-        "stackFrames", "stackFrames",
+        TraceLog::GetCategoryGroupEnabled("__metadata"), "stackFrames",
+        "stackFrames",
         scoped_refptr<ConvertableToTraceFormat>(stack_frame_deduplicator));
     TRACE_EVENT_API_ADD_METADATA_EVENT(
-        "typeNames", "typeNames",
+        TraceLog::GetCategoryGroupEnabled("__metadata"), "typeNames",
+        "typeNames",
         scoped_refptr<ConvertableToTraceFormat>(type_name_deduplicator));
   }
 
   DCHECK(!dump_thread_);
   dump_thread_ = std::move(dump_thread);
   session_state_ = new MemoryDumpSessionState(stack_frame_deduplicator,
                                               type_name_deduplicator);
 
   subtle::NoBarrier_Store(&memory_tracing_enabled_, 1);
 
@@ skipping 109 matching lines @@
   auto iter = process_dumps.find(pid);
   if (iter == process_dumps.end()) {
     scoped_ptr<ProcessMemoryDump> new_pmd(new ProcessMemoryDump(session_state));
     iter = process_dumps.insert(std::make_pair(pid, std::move(new_pmd))).first;
   }
   return iter->second.get();
 }
 
 }  // namespace trace_event
 }  // namespace base