enforce 16byte alignment in shader contexts

src/core/SkBitmapProcShader.cpp

Index: src/core/SkBitmapProcShader.cpp
diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 895922c6b873a388210e0887d768f08dc05646c5..6c87ebeda463c279a7dfd75198934f37d52ef187 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -120,7 +120,7 @@ private:
 size_t SkBitmapProcShader::ContextSize(const ContextRec& rec) {
     // The SkBitmapProcState is stored outside of the context object, with the context holding
     // a pointer to it.
-    return sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
+    return SkAlign16(sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState));
 }
 
 SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,