enforce 16byte alignment in shader contexts

src/effects/gradients/SkLinearGradient.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkLinearGradient_DEFINED
 #define SkLinearGradient_DEFINED
 
@@ skipping 15 matching lines @@
 
 class SkLinearGradient : public SkGradientShaderBase {
 public:
     enum {
         // Temp flag for testing the 4f impl.
         kForce4fContext_PrivateFlag     = 1 << 7,
     };
 
     SkLinearGradient(const SkPoint pts[2], const Descriptor&);
 
-    size_t contextSize(const ContextRec&) const override;
-
     class LinearGradientContext : public SkGradientShaderBase::GradientShaderBaseContext {
     public:
         LinearGradientContext(const SkLinearGradient&, const ContextRec&);
 
         void shadeSpan(int x, int y, SkPMColor dstC[], int count) override;
 
         struct Rec {
             Sk4fStorage fColor;
             float       fPos;
             float       fPosScale;
@@ skipping 16 matching lines @@
                                                    const SkMatrix*,
                                                    SkFilterQuality) const override;
 #endif
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLinearGradient)
 
 protected:
     SkLinearGradient(SkReadBuffer& buffer);
     void flatten(SkWriteBuffer& buffer) const override;
+    size_t onContextSize(const ContextRec&) const override;
     Context* onCreateContext(const ContextRec&, void* storage) const override;
 
 private:
     class LinearGradient4fContext;
 
     friend class SkGradientShader;
     typedef SkGradientShaderBase INHERITED;
     const SkPoint fStart;
     const SkPoint fEnd;
 };
 
 #endif