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

gm/anisotropic.cpp

Index: gm/anisotropic.cpp
diff --git a/gm/anisotropic.cpp b/gm/anisotropic.cpp
index 3e573c4d36f63c4f0c9ee9b207352d4d191ac661..d8f9181286f333c0112f9dca81373cb946b3f0bf 100644
--- a/gm/anisotropic.cpp
+++ b/gm/anisotropic.cpp
@@ -27,9 +27,9 @@ protected:
 
     // Create an image consisting of lines radiating from its center
     void onOnceBeforeDraw() override {
-        static const int kNumLines = 100;
-        static const SkScalar kAngleStep = 360.0f / kNumLines;
-        static const int kInnerOffset = 10;
+        constexpr int kNumLines = 100;
+        constexpr SkScalar kAngleStep = 360.0f / kNumLines;
+        constexpr int kInnerOffset = 10;
 
         fBM.allocN32Pixels(kImageSize, kImageSize, true);
 
@@ -97,9 +97,9 @@ protected:
     }
 
 private:
-    static const int kImageSize     = 256;
-    static const int kSpacer        = 10;
-    static const int kNumVertImages = 5;
+    static constexpr int kImageSize     = 256;
+    static constexpr int kSpacer        = 10;
+    static constexpr int kNumVertImages = 5;
 
     SkBitmap         fBM;
     SkFilterQuality  fFilterQuality;