enforce 16byte alignment in shader contexts

src/effects/gradients/SkLinearGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Sk4fLinearGradient.h"
 #include "SkLinearGradient.h"
 
@@ skipping 70 matching lines @@
     return SkGradientShader::CreateLinear(pts, desc.fColors, desc.fPos, desc.fCount,
                                           desc.fTileMode, desc.fGradFlags, desc.fLocalMatrix);
 }
 
 void SkLinearGradient::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fStart);
     buffer.writePoint(fEnd);
 }
 
-size_t SkLinearGradient::contextSize(const ContextRec& rec) const {
+size_t SkLinearGradient::onContextSize(const ContextRec& rec) const {
     return use_4f_context(rec, fGradFlags)
-        ? sizeof(LinearGradient4fContext)
-        : sizeof(LinearGradientContext);
+        ? SkAlign16(sizeof(LinearGradient4fContext))
+        : SkAlign16(sizeof(LinearGradientContext));
 }
 
 SkShader::Context* SkLinearGradient::onCreateContext(const ContextRec& rec, void* storage) const {
     return use_4f_context(rec, fGradFlags)
         ? static_cast<SkShader::Context*>(new (storage) LinearGradient4fContext(*this, rec))
         : static_cast<SkShader::Context*>(new (storage) LinearGradientContext(*this, rec));
 }
 
 // This swizzles SkColor into the same component order as SkPMColor, but does not actually
 // "pre" multiply the color components.
@@ skipping 657 matching lines @@
             this->shade4_dx_clamp<false, true>(dstC, count, fx, dx, invDx, dither);
         }
     } else {
         if (fApplyAlphaAfterInterp) {
             this->shade4_dx_clamp<true, false>(dstC, count, fx, dx, invDx, dither);
         } else {
             this->shade4_dx_clamp<false, false>(dstC, count, fx, dx, invDx, dither);
         }
     }
 }