enforce 16byte alignment in shader contexts

src/core/SkLocalMatrixShader.h

Index: src/core/SkLocalMatrixShader.h
diff --git a/src/core/SkLocalMatrixShader.h b/src/core/SkLocalMatrixShader.h
index d897d49ded4cdd455472626a0190df6f7f9080be..8edea40d05bd1d896bcca7d31ef86bb96ddb4716 100644
--- a/src/core/SkLocalMatrixShader.h
+++ b/src/core/SkLocalMatrixShader.h
@@ -19,10 +19,6 @@ public:
     , fProxyShader(SkRef(proxy))
     {}
 
-    size_t contextSize(const ContextRec& rec) const override {
-        return fProxyShader->contextSize(rec);
-    }
-
     GradientType asAGradient(GradientInfo* info) const override {
         return fProxyShader->asAGradient(info);
     }
@@ -53,6 +49,10 @@ protected:
     void flatten(SkWriteBuffer&) const override;
     Context* onCreateContext(const ContextRec&, void*) const override;
 
+    size_t onContextSize(const ContextRec& rec) const override {
+        return fProxyShader->contextSize(rec);
+    }
+
     bool onIsABitmap(SkBitmap* bitmap, SkMatrix* matrix, TileMode* mode) const override {
         return fProxyShader->isABitmap(bitmap, matrix, mode);
     }