Add support for TraceEvent before the native library is loaded.

base/debug/trace_event.h

 // 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.
 
 // This header file defines the set of trace_event macros without specifying
 // how the events actually get collected and stored. If you need to expose trace
 // events to some other universe, you can copy-and-paste this file as well as
 // trace_event.h, modifying the macros contained there as necessary for the
 // target platform. The end result is that multiple libraries can funnel events
 // through to a shared trace event collector.
@@ skipping 1019 matching lines @@
 // Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT.
 #define TRACE_EVENT_FLAG_NONE         (static_cast<unsigned char>(0))
 #define TRACE_EVENT_FLAG_COPY         (static_cast<unsigned char>(1 << 0))
 #define TRACE_EVENT_FLAG_HAS_ID       (static_cast<unsigned char>(1 << 1))
 #define TRACE_EVENT_FLAG_MANGLE_ID    (static_cast<unsigned char>(1 << 2))
 #define TRACE_EVENT_FLAG_SCOPE_OFFSET (static_cast<unsigned char>(1 << 3))
 
 #define TRACE_EVENT_FLAG_SCOPE_MASK   (static_cast<unsigned char>( \
     TRACE_EVENT_FLAG_SCOPE_OFFSET | (TRACE_EVENT_FLAG_SCOPE_OFFSET << 1)))
 
+#define TRACE_EVENT_FLAG_DONT_REPORT_OVERHEAD \
+    (static_cast<unsigned char>(1 << 5))
+
 // Type values for identifying types in the TraceValue union.
 #define TRACE_VALUE_TYPE_BOOL         (static_cast<unsigned char>(1))
 #define TRACE_VALUE_TYPE_UINT         (static_cast<unsigned char>(2))
 #define TRACE_VALUE_TYPE_INT          (static_cast<unsigned char>(3))
 #define TRACE_VALUE_TYPE_DOUBLE       (static_cast<unsigned char>(4))
 #define TRACE_VALUE_TYPE_POINTER      (static_cast<unsigned char>(5))
 #define TRACE_VALUE_TYPE_STRING       (static_cast<unsigned char>(6))
 #define TRACE_VALUE_TYPE_COPY_STRING  (static_cast<unsigned char>(7))
 #define TRACE_VALUE_TYPE_CONVERTABLE  (static_cast<unsigned char>(8))
 
@@ skipping 530 matching lines @@
   const char* name_;
   IDType id_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceScopedTrackableObject);
 };
 
 } // namespace debug
 } // namespace base
 
 #endif /* BASE_DEBUG_TRACE_EVENT_H_ */