fix stroked text underline / strikethrough

gm/texteffects.cpp

Index: gm/texteffects.cpp
diff --git a/gm/texteffects.cpp b/gm/texteffects.cpp
index 53395f0732f2e22a42e50bd9779f2e35d3fce72e..1d4b98e950fdd16a12c7076c4a47d022010ea9e7 100644
--- a/gm/texteffects.cpp
+++ b/gm/texteffects.cpp
@@ -196,3 +196,35 @@ DEF_SIMPLE_GM(texteffects, canvas, 460, 680) {
 
         canvas->restore();
 }
+
+DEF_SIMPLE_GM(textunderstrike, canvas, 460, 680) {
+    canvas->clear(SK_ColorYELLOW);
+    SkPaint paint;
+    sk_tool_utils::set_portable_typeface(&paint);
+    paint.setTextSize(50);
+    paint.setStrokeWidth(5);
+    paint.setAntiAlias(true);
+
+    auto drawText = [&]() {
+        paint.setStyle(SkPaint::kFill_Style);
+        canvas->drawText("Hello", 5, 100, 50, paint);
+        paint.setStyle(SkPaint::kStroke_Style);
+        canvas->drawText("Hello", 5, 100, 100, paint);
+        canvas->translate(0, 100);
+    };
+
+    drawText();
+    paint.setUnderlineText(true);
+    drawText();
+    paint.setUnderlineText(false);
+    paint.setStrikeThruText(true);
+    drawText();
+    paint.setUnderlineText(true);
+    drawText();
+    paint.setColor(SK_ColorWHITE);
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas->drawText("Hello", 5, 100, 50, paint);
+    paint.setColor(SK_ColorBLUE);
+    paint.setStyle(SkPaint::kFill_Style);
+    canvas->drawText("Hello", 5, 100, 50, paint);
+}