enforce 16byte alignment in shader contexts

src/core/SkColorFilterShader.cpp

Index: src/core/SkColorFilterShader.cpp
diff --git a/src/core/SkColorFilterShader.cpp b/src/core/SkColorFilterShader.cpp
index 7b421e9b6dc2ed323b238e0fc60dd912898e85b6..c856f19150cffc5d2fee7befaa2d30e068f717c8 100644
--- a/src/core/SkColorFilterShader.cpp
+++ b/src/core/SkColorFilterShader.cpp
@@ -62,8 +62,8 @@ SkShader::Context* SkColorFilterShader::onCreateContext(const ContextRec& rec,
     return new (storage) FilterShaderContext(*this, shaderContext, rec);
 }
 
-size_t SkColorFilterShader::contextSize(const ContextRec& rec) const {
-    return sizeof(FilterShaderContext) + fShader->contextSize(rec);
+size_t SkColorFilterShader::onContextSize(const ContextRec& rec) const {
+    return SkAlign16(sizeof(FilterShaderContext)) + fShader->contextSize(rec);
 }
 
 SkColorFilterShader::FilterShaderContext::FilterShaderContext(