Merge "don't clear the framebuffer when the framebuffer is not used" into ics-factoryrom

void SurfaceFlinger::composeSurfaces(const Region& dirty)

{

    if (UNLIKELY(!mWormholeRegion.isEmpty())) {

    const DisplayHardware& hw(graphicPlane(0).displayHardware());

    HWComposer& hwc(hw.getHwComposer());

    const size_t fbLayerCount = hwc.getLayerCount(HWC_FRAMEBUFFER);

    if (UNLIKELY(fbLayerCount && !mWormholeRegion.isEmpty())) {

        // should never happen unless the window manager has a bug

        // draw something...

        drawWormhole();

    }

    const DisplayHardware& hw(graphicPlane(0).displayHardware());

    HWComposer& hwc(hw.getHwComposer());

    hwc_layer_t* const cur(hwc.getLayers());

    /*

     * and then, render the layers targeted at the framebuffer

     */

    hwc_layer_t* const cur(hwc.getLayers());

    const Vector< sp<LayerBase> >& layers(mVisibleLayersSortedByZ);

    size_t count = layers.size();

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