[tracing] Add trace events filtering predicate for heap profiler

base/trace_event/trace_log_constants.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 "base/trace_event/trace_log.h"
 
 namespace base {
 namespace trace_event {
 
 // Constant used by TraceLog's internal implementation of trace_option.
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalNone = 0;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalRecordUntilFull = 1 << 0;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalRecordContinuously = 1 << 1;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalEnableSampling = 1 << 2;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalEchoToConsole = 1 << 3;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalRecordAsMuchAsPossible = 1 << 4;
 const TraceLog::InternalTraceOptions
     TraceLog::kInternalEnableArgumentFilter = 1 << 5;
 
+// TraceEventFilter predicate names used in trace config.
+const char* const TraceLog::TraceEventFilter::kEventWhitelistPredicate =
+    "event_whitelist_predicate";
+const char* const TraceLog::TraceEventFilter::kHeapProfilerPredicate =
+    "heap_profiler_predicate";
+
 }  // namespace trace_event
 }  // namespace base