Merge "Ensure FrameTracer is only initialized once."

#include <android-base/stringprintf.h>

#include <algorithm>

#include <mutex>

PERFETTO_DEFINE_DATA_SOURCE_STATIC_MEMBERS(android::FrameTracer::FrameTracerDataSource);

namespace android {

void FrameTracer::initialize() {

    std::call_once(mInitializationFlag, [this]() {

        perfetto::TracingInitArgs args;

        args.backends = perfetto::kSystemBackend;

        perfetto::Tracing::Initialize(args);

        registerDataSource();

    });

}

void FrameTracer::registerDataSource() {

    std::mutex mTraceMutex;

    std::unordered_map<int32_t, TraceRecord> mTraceTracker;

    std::once_flag mInitializationFlag;

};

} // namespace android