Add support for TraceEvent before the native library is loaded.

base/android/early_trace_event.h

+// 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.
+
+#ifndef BASE_ANDROID_EARLY_TRACE_EVENT_H_
+#define BASE_ANDROID_EARLY_TRACE_EVENT_H_
+
+#include <jni.h>
+
+#include <string>
+#include <vector>
+
+#include "base/time/time.h"
+
+namespace base {
+namespace android {
+
+bool RegisterEarlyTraceEvent(JNIEnv* env);
+
+// A trace event that was recorded before the native library was initialized.
+struct EarlyTraceEvent {
+  EarlyTraceEvent();
+  ~EarlyTraceEvent();
+
+  std::string name;
+  long thread_id;
+  TimeTicks begin_timestamp;
+  TimeTicks begin_thread_time;
+  TimeTicks end_timestamp;
+  TimeTicks end_thread_time;
+};
+
+void GetAllEarlyTraceEvents(std::vector<EarlyTraceEvent>* trace_events);
+
+}  // namespace android
+}  // namespace base
+
+#endif  // BASE_ANDROID_EARLY_TRACE_EVENT_H_