don't leak the bitmapShader

src/core/SkPictureShader.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPictureShader.h"
 
 #include "SkBitmap.h"
@@ skipping 101 matching lines @@
 
 size_t SkPictureShader::contextSize() const {
     return sizeof(PictureShaderContext);
 }
 
 SkShader::Context* SkPictureShader::onCreateContext(const ContextRec& rec, void* storage) const {
     SkAutoTUnref<SkShader> bitmapShader(this->refBitmapShader(*rec.fMatrix));
     if (NULL == bitmapShader.get()) {
         return NULL;
     }
-    return PictureShaderContext::Create(storage, *this, rec, bitmapShader.detach());
+    return PictureShaderContext::Create(storage, *this, rec, bitmapShader);
 }
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
 SkShader::Context* SkPictureShader::PictureShaderContext::Create(void* storage,
                    const SkPictureShader& shader, const ContextRec& rec, SkShader* bitmapShader) {
     PictureShaderContext* ctx = SkNEW_PLACEMENT_ARGS(storage, PictureShaderContext,
                                                      (shader, rec, bitmapShader));
     if (NULL == ctx->fBitmapShaderContext) {
         ctx->~PictureShaderContext();
@@ skipping 57 matching lines @@
 
 #if SK_SUPPORT_GPU
 GrEffectRef* SkPictureShader::asNewEffect(GrContext* context, const SkPaint& paint) const {
     SkAutoTUnref<SkShader> bitmapShader(this->refBitmapShader(context->getMatrix()));
     if (!bitmapShader) {
         return NULL;
     }
     return bitmapShader->asNewEffect(context, paint);
 }
 #endif