Merge "Guard against crash due to null surface" into pi-dev

    sp<RefBase> obj;

    CHECK(msg->findObject("input-surface", &obj));

    if (obj == NULL) {

        ALOGE("[%s] NULL input surface", mCodec->mComponentName.c_str());

        mCodec->mCallback->onInputSurfaceDeclined(BAD_VALUE);

        return;

    }

    sp<PersistentSurface> surface = static_cast<PersistentSurface *>(obj.get());

    mCodec->mGraphicBufferSource = surface->getBufferSource();

    status_t err = setupInputSurface();

    if (err == OK) {