Merge "Fix dumpsys SurfaceFlinger --frame-events"

void SurfaceFlinger::dumpFrameEventsLocked(std::string& result) {

    result.append("Layer frame timestamps:\n");

    const LayerVector& currentLayers = mCurrentState.layersSortedByZ;

    const size_t count = currentLayers.size();

    for (size_t i=0 ; i<count ; i++) {

        currentLayers[i]->dumpFrameEvents(result);

    }

    // Traverse all layers to dump frame-events for each layer

    mCurrentState.traverseInZOrder(

        [&] (Layer* layer) { layer->dumpFrameEvents(result); });

}

void SurfaceFlinger::dumpBufferingStats(std::string& result) const {