GM: replace boilerplate with macros

gm/beziereffects.cpp

Index: gm/beziereffects.cpp
diff --git a/gm/beziereffects.cpp b/gm/beziereffects.cpp
index ff75f74c669cb0ed16a98bc0daf10f918b11c357..1886a4a2b0ae811503045fc42a389dadd4736838 100644
--- a/gm/beziereffects.cpp
+++ b/gm/beziereffects.cpp
@@ -122,7 +122,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
         if (nullptr == rt) {
-            this->drawGpuOnlyMessage(canvas);
+            skiagm::GM::DrawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
@@ -270,7 +270,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
         if (nullptr == rt) {
-            this->drawGpuOnlyMessage(canvas);
+            skiagm::GM::DrawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
@@ -513,7 +513,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
         if (nullptr == rt) {
-            this->drawGpuOnlyMessage(canvas);
+            skiagm::GM::DrawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();