add support for new bitmapshader context

src/core/SkComposeShader.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkComposeShader.h"
 #include "SkColorFilter.h"
 #include "SkColorPriv.h"
@@ skipping 13 matching lines @@
     SkSafeRef(mode);
 }
 
 SkComposeShader::~SkComposeShader() {
     SkSafeUnref(fMode);
     fShaderB->unref();
     fShaderA->unref();
 }
 
 size_t SkComposeShader::contextSize(const ContextRec& rec) const {
-    return sizeof(ComposeShaderContext)
-        + fShaderA->contextSize(rec)
-        + fShaderB->contextSize(rec);
+    return SkAlign16(sizeof(ComposeShaderContext))
+         + SkAlign16(fShaderA->contextSize(rec))
+         + SkAlign16(fShaderB->contextSize(rec));
 }
 
 class SkAutoAlphaRestore {
 public:
     SkAutoAlphaRestore(SkPaint* paint, uint8_t newAlpha) {
         fAlpha = paint->getAlpha();
         fPaint = paint;
         paint->setAlpha(newAlpha);
     }
 
@@ skipping 22 matching lines @@
     buffer.writeFlattenable(fMode);
 }
 
 template <typename T> void safe_call_destructor(T* obj) {
     if (obj) {
         obj->~T();
     }
 }
 
 SkShader::Context* SkComposeShader::onCreateContext(const ContextRec& rec, void* storage) const {
-    char* aStorage = (char*) storage + sizeof(ComposeShaderContext);
-    char* bStorage = aStorage + fShaderA->contextSize(rec);
+    char* aStorage = (char*) storage + SkAlign16(sizeof(ComposeShaderContext));
+    char* bStorage = aStorage + SkAlign16(fShaderA->contextSize(rec));
 
     // we preconcat our localMatrix (if any) with the device matrix
     // before calling our sub-shaders
     SkMatrix tmpM;
     tmpM.setConcat(*rec.fMatrix, this->getLocalMatrix());
 
     // Our sub-shaders need to see opaque, so by combining them we don't double-alphatize the
     // result. ComposeShader itself will respect the alpha, and post-apply it after calling the
     // sub-shaders.
     SkPaint opaquePaint(*rec.fPaint);
@@ skipping 168 matching lines @@
     if (!dst || !src) {
         return nullptr;
     }
     return new SkComposeShader(dst, src, xfer);
 }
 
 SkShader* SkShader::CreateComposeShader(SkShader* dst, SkShader* src, SkXfermode::Mode mode) {
     SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(mode));
     return CreateComposeShader(dst, src, xfer);
 }