SkPMFloat: fewer internal this->isValid() assertions.

src/opts/SkPMFloat_none.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 inline SkPMFloat::SkPMFloat(SkPMColor c) {
     *this = SkPMFloat::FromARGB(SkGetPackedA32(c),
                                 SkGetPackedR32(c),
                                 SkGetPackedG32(c),
                                 SkGetPackedB32(c));
     SkASSERT(this->isValid());
 }
 
 inline SkPMColor SkPMFloat::trunc() const {
     return SkPackARGB32(this->a(), this->r(), this->g(), this->b());
 }
 
 inline SkPMColor SkPMFloat::get() const {
-    SkASSERT(this->isValid());
-    return SkPackARGB32(this->a()+0.5f, this->r()+0.5f, this->g()+0.5f, this->b()+0.5f);
+    SkPMColor c = SkPackARGB32(this->a()+0.5f, this->r()+0.5f, this->g()+0.5f, this->b()+0.5f);
+    SkPMColorAssert(c);
+    return c;
 }
 
 inline SkPMColor SkPMFloat::clamped() const {
     float a = this->a(),
           r = this->r(),
           g = this->g(),
           b = this->b();
     a = a < 0 ? 0 : (a > 255 ? 255 : a);
     r = r < 0 ? 0 : (r > 255 ? 255 : r);
     g = g < 0 ? 0 : (g > 255 ? 255 : g);
     b = b < 0 ? 0 : (b > 255 ? 255 : b);
-    return SkPackARGB32(a+0.5f, r+0.5f, g+0.5f, b+0.5f);
+    SkPMColor c = SkPackARGB32(a+0.5f, r+0.5f, g+0.5f, b+0.5f);
+    SkPMColorAssert(c);
+    return c;
 }
 
 inline void SkPMFloat::From4PMColors(const SkPMColor colors[4],
                                      SkPMFloat* a, SkPMFloat* b, SkPMFloat* c, SkPMFloat* d) {
     *a = FromPMColor(colors[0]);
     *b = FromPMColor(colors[1]);
     *c = FromPMColor(colors[2]);
     *d = FromPMColor(colors[3]);
 }
 
 inline void SkPMFloat::To4PMColors(
         const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d,
         SkPMColor colors[4]) {
     colors[0] = a.get();
     colors[1] = b.get();
     colors[2] = c.get();
     colors[3] = d.get();
 }
 
 inline void SkPMFloat::ClampTo4PMColors(
         const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d,
         SkPMColor colors[4]) {
     colors[0] = a.clamped();
     colors[1] = b.clamped();
     colors[2] = c.clamped();
     colors[3] = d.clamped();
 }