gm: add some overrides

Change-Id: I5348e2da1a2034b629d43b9e9faadb6db333abe8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/228348
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
diff --git a/gm/clockwise.cpp b/gm/clockwise.cpp
index a9ee63d..55c312f 100644
--- a/gm/clockwise.cpp
+++ b/gm/clockwise.cpp
@@ -58,7 +58,7 @@
 class GrAppliedClip;
 class GrGLSLProgramDataManager;
 
-namespace skiagm {
+namespace {
 
 static constexpr GrGeometryProcessor::Attribute gVertex =
         {"position", kFloat2_GrVertexAttribType, kFloat2_GrSLType};
@@ -68,10 +68,9 @@
  * triangles (sk_Clockwise), in terms of to Skia device space, in all backends and with all render
  * target origins. We draw clockwise triangles green and counter-clockwise red.
  */
-class ClockwiseGM : public GpuGM {
-private:
-    SkString onShortName() final { return SkString("clockwise"); }
-    SkISize onISize() override { return SkISize::Make(300, 200); }
+class ClockwiseGM : public skiagm::GpuGM {
+    SkString onShortName() override { return SkString("clockwise"); }
+    SkISize onISize() override { return {300, 200}; }
     void onDraw(GrContext*, GrRenderTargetContext*, SkCanvas*) override;
 };