enforce 16byte alignment in shader contexts

src/image/SkImageShader.cpp

Index: src/image/SkImageShader.cpp
diff --git a/src/image/SkImageShader.cpp b/src/image/SkImageShader.cpp
index a07603c671863cd97c44363975a9fa52ccbb9542..4c7ded906ceeefd21ee55a5ecb69e1d788de8a80 100644
--- a/src/image/SkImageShader.cpp
+++ b/src/image/SkImageShader.cpp
@@ -42,7 +42,7 @@ bool SkImageShader::isOpaque() const {
     return fImage->isOpaque();
 }
 
-size_t SkImageShader::contextSize(const ContextRec& rec) const {
+size_t SkImageShader::onContextSize(const ContextRec& rec) const {
     return SkBitmapProcShader::ContextSize(rec);
 }