Use SkTextEncoding enum instead of macros.

Change-Id: I4b6259590fa0693ee0522b4999a1c0fe250b173d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212504
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/gm/convexpolyclip.cpp b/gm/convexpolyclip.cpp
index 08c5160..31dc1d4 100644
--- a/gm/convexpolyclip.cpp
+++ b/gm/convexpolyclip.cpp
@@ -79,12 +79,12 @@
     paint.setColor(SK_ColorLTGRAY);
     constexpr char kTxt[] = "Skia";
     SkPoint texPos = { wScalar / 17, hScalar / 2 + font.getSize() / 2.5f };
-    canvas.drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, kUTF8_SkTextEncoding,
+    canvas.drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, SkTextEncoding::kUTF8,
                           texPos.fX, texPos.fY, font, paint);
     paint.setColor(SK_ColorBLACK);
     paint.setStyle(SkPaint::kStroke_Style);
     paint.setStrokeWidth(SK_Scalar1);
-    canvas.drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, kUTF8_SkTextEncoding,
+    canvas.drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, SkTextEncoding::kUTF8,
                           texPos.fX, texPos.fY, font, paint);
     return bmp;
 }
@@ -166,7 +166,7 @@
 
         constexpr char kTxt[] = "Clip Me!";
         SkFont         font(ToolUtils::create_portable_typeface(), 23);
-        SkScalar textW = font.measureText(kTxt, SK_ARRAY_COUNT(kTxt)-1, kUTF8_SkTextEncoding);
+        SkScalar textW = font.measureText(kTxt, SK_ARRAY_COUNT(kTxt)-1, SkTextEncoding::kUTF8);
         SkPaint txtPaint;
         txtPaint.setColor(SK_ColorDKGRAY);
 
@@ -217,7 +217,7 @@
                     canvas->drawPath(closedClipPath, clipOutlinePaint);
                     clip->setOnCanvas(canvas, kIntersect_SkClipOp, SkToBool(aa));
                     canvas->scale(1.f, 1.8f);
-                    canvas->drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, kUTF8_SkTextEncoding,
+                    canvas->drawSimpleText(kTxt, SK_ARRAY_COUNT(kTxt)-1, SkTextEncoding::kUTF8,
                                      0, 1.5f * font.getSize(), font, txtPaint);
                     canvas->restore();
                     x += textW + 2 * kMargin;