Replace a lot of 'static const' with 'constexpr' or 'const'.

gm/bmpfilterqualityrepeat.cpp

Index: gm/bmpfilterqualityrepeat.cpp
diff --git a/gm/bmpfilterqualityrepeat.cpp b/gm/bmpfilterqualityrepeat.cpp
index 6264d74df284eb02d1fbdad5e6f0b8bf712c8c6b..c55626f6b2eb1e16ce6e7ea4b9656c4f81cd1ad4 100644
--- a/gm/bmpfilterqualityrepeat.cpp
+++ b/gm/bmpfilterqualityrepeat.cpp
@@ -39,7 +39,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
 
-        static const struct {
+        constexpr struct {
             SkFilterQuality fQuality;
             const char* fName;
         } kQualities[] = {
@@ -59,7 +59,7 @@ protected:
             lm.setTranslateX(423);
             lm.setTranslateY(330);
 
-            static const SkShader::TileMode kTM = SkShader::kRepeat_TileMode;
+            constexpr SkShader::TileMode kTM = SkShader::kRepeat_TileMode;
             bmpPaint.setShader(SkShader::MakeBitmapShader(fBmp, kTM, kTM, &lm));
             SkRect rect = SkRect::MakeLTRB(20, 60, 220, 210);
             canvas->drawRect(rect, bmpPaint);