SF: Remove unused globals of VSYNC sysprops

    static char const* getServiceName() ANDROID_API { return "SurfaceFlinger"; }

    // This is the phase offset in nanoseconds of the software vsync event

    // relative to the vsync event reported by HWComposer.  The software vsync

    // event is when SurfaceFlinger and Choreographer-based applications run each

    // frame.

    //

    // This phase offset allows adjustment of the minimum latency from application

    // wake-up time (by Choreographer) to the time at which the resulting window

    // image is displayed.  This value may be either positive (after the HW vsync)

    // or negative (before the HW vsync). Setting it to 0 will result in a lower

    // latency bound of two vsync periods because the app and SurfaceFlinger

    // will run just after the HW vsync.  Setting it to a positive number will

    // result in the minimum latency being:

    //

    //     (2 * VSYNC_PERIOD - (vsyncPhaseOffsetNs % VSYNC_PERIOD))

    //

    // Note that reducing this latency makes it more likely for the applications

    // to not have their window content image ready in time.  When this happens

    // the latency will end up being an additional vsync period, and animations

    // will hiccup.  Therefore, this latency should be tuned somewhat

    // conservatively (or at least with awareness of the trade-off being made).

    static int64_t vsyncPhaseOffsetNs;

    static int64_t sfVsyncPhaseOffsetNs;

    // If fences from sync Framework are supported.

    static bool hasSyncFramework;