GM: replace boilerplate with macros

gm/glyph_pos_align.cpp

Index: gm/glyph_pos_align.cpp
diff --git a/gm/glyph_pos_align.cpp b/gm/glyph_pos_align.cpp
index 9add494ffd035a24455c3e8f1d1886b378ab951a..e80955e1acc91d121b1ed663a1e2bc904db71cec 100644
--- a/gm/glyph_pos_align.cpp
+++ b/gm/glyph_pos_align.cpp
@@ -17,20 +17,9 @@ static const int kHeight = 600;
 static const SkScalar kTextHeight = 64.0f;
 static const int kMaxStringLength = 12;
 
-namespace skiagm {
-
-class GlyphPosAlignGM : public GM {
-protected:
-
-    SkString onShortName() override {
-        return SkString("glyph_pos_align");
-    }
-
-    SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
-
-    void onDraw(SkCanvas* canvas) override {
-        canvas->clear(SK_ColorBLACK);
+static void drawTestCase(SkCanvas*, const char*, SkScalar, const SkPaint&);
 
+DEF_SIMPLE_GM_BG(glyph_pos_align, canvas, kWidth, kHeight, SK_ColorBLACK) {
         SkPaint paint;
         paint.setTextSize(kTextHeight);
         paint.setFakeBoldText(true);
@@ -50,9 +39,9 @@ protected:
 
         paint.setTextAlign(SkPaint::kLeft_Align);
         drawTestCase(canvas, "Left Align", 7 * kTextHeight, paint);
-    }
+}
 
-    void drawTestCase(SkCanvas* canvas, const char* text, SkScalar y, const SkPaint& paint) {
+void drawTestCase(SkCanvas* canvas, const char* text, SkScalar y, const SkPaint& paint) {
         SkScalar widths[kMaxStringLength];
         SkScalar posX[kMaxStringLength];
         SkPoint pos[kMaxStringLength];
@@ -78,19 +67,4 @@ protected:
 
         canvas->drawPosTextH(text, length, posX, y, paint);
         canvas->drawPosText(text, length, pos, paint);
-    }
-
-private:
-
-    typedef GM INHERITED;
-};
-
-//////////////////////////////////////////////////////////////////////////////
-
-static GM* GlyphPosAlignFactory(void*) {
-    return new GlyphPosAlignGM();
-}
-
-static GMRegistry reg(GlyphPosAlignFactory);
-
 }