https://fiddle.skia.org/c/696fce03d0483f6933c988c14493d49f

SkiaGrid1.cpp

void draw(SkCanvas* canvas) {

    SkPaint paint1;
    SkPaint paint2;

    float width = 120.0f;
    float height = 90.0f;
    float cw = 15.0f;
    float ch = 15.0f;

    SkMatrix lattice1;
    lattice1.setScale(cw, ch);
    lattice1.preRotate(0.0f);
    lattice1.preTranslate(-cw, 0.0f);

    SkMatrix lattice2;
    lattice2.setScale(cw, ch);
    lattice2.preRotate(90.0f);
    lattice2.preTranslate(0.0f, -ch);

    canvas->clear(SK_ColorWHITE);

    paint1.setAntiAlias(false);
    paint1.setPathEffect(SkLine2DPathEffect::Make(1.0f, lattice1));
    SkRect bounds1 = SkRect::MakeXYWH(cw, -ch, width, height);

    paint2.setAntiAlias(false);
    paint2.setPathEffect(SkLine2DPathEffect::Make(1.0f, lattice2));
    SkRect bounds2 = SkRect::MakeXYWH(-cw, ch, width, height);

    canvas->drawRect(bounds1, paint1);
    canvas->drawRect(bounds2, paint2);

    SkPaint strokePaint;
    strokePaint.setAntiAlias(false);
    strokePaint.setStrokeWidth(1.0f);
    strokePaint.setColor(SkColorSetARGB(0xFF, 0xFF, 0x00, 0x00));
    strokePaint.setStyle(SkPaint::kStroke_Style);
    canvas->drawRect(SkRect::MakeXYWH(0.0f, 0.0f, width, height), strokePaint);

}

SkiaGrid2.cpp

void draw(SkCanvas* canvas) {

    SkPaint paint1;
    SkPaint paint2;

    float width = 120.0f;
    float height = 90.0f;
    float cw = 15.0f;
    float ch = 15.0f;

    SkMatrix lattice1;
    lattice1.setScale(cw, ch);
    lattice1.preRotate(0.0f);
    //lattice1.preTranslate(-cw, 0.0f);

    SkMatrix lattice2;
    lattice2.setScale(cw, ch);
    lattice2.preRotate(90.0f);
    //lattice2.preTranslate(0.0f, -ch);

    canvas->clear(SK_ColorWHITE);

    paint1.setAntiAlias(false);
    paint1.setPathEffect(SkLine2DPathEffect::Make(1.0f, lattice1));
    SkRect bounds1 = SkRect::MakeXYWH(0.0f, ch, width, height - ch);

    paint2.setAntiAlias(false);
    paint2.setPathEffect(SkLine2DPathEffect::Make(1.0f, lattice2));
    SkRect bounds2 = SkRect::MakeXYWH(cw, 0.0f, width - cw, height);

    canvas->drawRect(bounds1, paint1);
    canvas->drawRect(bounds2, paint2);

    SkPaint strokePaint;
    strokePaint.setAntiAlias(false);
    strokePaint.setStrokeWidth(1.0f);
    strokePaint.setColor(SkColorSetARGB(0xFF, 0xFF, 0x00, 0x00));
    strokePaint.setStyle(SkPaint::kStroke_Style);
    canvas->drawRect(SkRect::MakeXYWH(0.0f, 0.0f, width, height), strokePaint);

}