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

gm/dashcircle.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkAnimTimer.h"
 #include "SkPath.h"
@@ skipping 77 matching lines @@
                 canvas->drawPath(circle, p);
                 canvas->restore();
                 canvas->translate(0, radius * 2 + 50);
             }
             canvas->restore();
             canvas->translate(radius * 2 + 50, 0);
         }
     }
 
     bool onAnimate(const SkAnimTimer& timer) override {
-        static const SkScalar kDesiredDurationSecs = 100.0f;
+        constexpr SkScalar kDesiredDurationSecs = 100.0f;
 
         fRotation = timer.scaled(360.0f/kDesiredDurationSecs, 360.0f);
         return true;
     }
 
 private:
     SkScalar fRotation;
 
     typedef GM INHERITED;
 };
 
 DEF_GM(return new DashCircleGM; )