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

gm/pixelsnap.cpp

 /*
  * Copyright 2015 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 "SkShader.h"
 
 // This class of GMs test how edges/verts snap near rounding boundaries in device space without
 // anti-aliaing.
 class PixelSnapGM : public skiagm::GM {
 public:
     PixelSnapGM() {}
 
 protected:
     // kTrans should be even or checkboards wont agree in different test cases.
-    static const int kTrans = 14;
-    static const int kLabelPad = 4;
+    static constexpr int kTrans = 14;
+    static constexpr int kLabelPad = 4;
     // The inverse of this value should be a perfect SkScalar.
-    static const int kSubPixelSteps = 8;
-    static const int kLabelTextSize = 9;
+    static constexpr int kSubPixelSteps = 8;
+    static constexpr int kLabelTextSize = 9;
 
     static_assert(kSubPixelSteps < 99, "label_offset_too_small");
-    static const int kLabelOffsetX = 2 * kLabelTextSize + kLabelPad;
-    static const int kLabelOffsetY = kLabelTextSize + kLabelPad;
+    static constexpr int kLabelOffsetX = 2 * kLabelTextSize + kLabelPad;
+    static constexpr int kLabelOffsetY = kLabelTextSize + kLabelPad;
 
     SkISize onISize() override {
         return SkISize::Make((kSubPixelSteps + 1) * kTrans + kLabelOffsetX + kLabelPad,
                              (kSubPixelSteps + 1) * kTrans + kLabelOffsetY + kLabelPad);
     }
 
     void onDraw(SkCanvas* canvas) override {
         SkPaint bgPaint;
         bgPaint.setShader(
                 sk_tool_utils::create_checkerboard_shader(
@@ skipping 133 matching lines @@
 
 private:
     typedef PixelSnapGM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 DEF_GM(return new PointSnapGM;)
 DEF_GM(return new LineSnapGM;)
 DEF_GM(return new RectSnapGM;)
 DEF_GM(return new ComboSnapGM;)