Refactor Sk2x<T> + Sk4x<T> into SkNf<N,T> and SkNi<N,T>

tests/PMFloatTest.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 "SkPMFloat.h"
 #include "Test.h"
 
@@ skipping 14 matching lines @@
     pmf = SkPMFloat(255.9f, 204.01f, 153.0f, -0.9f);
     REPORTER_ASSERT(r, SkPreMultiplyColor(0xFFCC9900) == pmf.trunc());
 
     // Test clamping.
     SkPMFloat clamped(SkPMFloat(510.0f, 153.0f, 1.0f, -0.2f).clamped());
     REPORTER_ASSERT(r, SkScalarNearlyEqual(255.0f, clamped.a()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual(153.0f, clamped.r()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual(  1.0f, clamped.g()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual(  0.0f, clamped.b()));
 
-    // Test SkPMFloat <-> Sk4f conversion.
-    Sk4f fs = clamped;
-    SkPMFloat scaled = fs * Sk4f(0.25f);
+    // Test SkPMFloat <-> Sk4s conversion.
+    Sk4s fs = clamped;
+    SkPMFloat scaled = fs * Sk4s(0.25f);
     REPORTER_ASSERT(r, SkScalarNearlyEqual(63.75f, scaled.a()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual(38.25f, scaled.r()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual( 0.25f, scaled.g()));
     REPORTER_ASSERT(r, SkScalarNearlyEqual( 0.00f, scaled.b()));
 
     // Test 4-at-a-time conversions.
     SkPMColor colors[4] = { 0xFF000000, 0xFFFF0000, 0xFF00FF00, 0xFF0000FF };
     SkPMFloat floats[4];
     SkPMFloat::From4PMColors(colors, floats+0, floats+1, floats+2, floats+3);
 
     SkPMColor back[4];
     SkPMFloat::To4PMColors(floats[0], floats[1], floats[2], floats[3], back);
     for (int i = 0; i < 4; i++) {
         REPORTER_ASSERT(r, back[i] == colors[i]);
     }
 
     SkPMFloat::ClampTo4PMColors(floats[0], floats[1], floats[2], floats[3], back);
     for (int i = 0; i < 4; i++) {
         REPORTER_ASSERT(r, back[i] == colors[i]);
     }
 }