enforce 16byte alignment in shader contexts

experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp

Index: experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
diff --git a/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp b/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
index a5a2a21523099464c4ceea8e294ad73b44fe2920..a1784a420443e5a0bdf757eeceedd4d7e2d7104e 100644
--- a/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
+++ b/experimental/SkPerlinNoiseShader2/SkPerlinNoiseShader2.cpp
@@ -571,8 +571,8 @@ SkShader::Context* SkPerlinNoiseShader2::onCreateContext(const ContextRec& rec,
     return new (storage) PerlinNoiseShaderContext(*this, rec);
 }
 
-size_t SkPerlinNoiseShader2::contextSize(const ContextRec&) const {
-    return sizeof(PerlinNoiseShaderContext);
+size_t SkPerlinNoiseShader2::onContextSize(const ContextRec&) const {
+    return SkAlign16(sizeof(PerlinNoiseShaderContext));
 }
 
 SkPerlinNoiseShader2::PerlinNoiseShaderContext::PerlinNoiseShaderContext(