Add ownership dox for SkShader::asACompose.

include/core/SkShader.h

 /*
  * 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.
  */
 
 
 #ifndef SkShader_DEFINED
 #define SkShader_DEFINED
@@ skipping 341 matching lines @@
         SkScalar    fRadius[2];     //!< Type specific, see above.
         TileMode    fTileMode;      //!< The tile mode used.
         uint32_t    fGradientFlags; //!< see SkGradientShader::Flags
     };
 
     virtual GradientType asAGradient(GradientInfo* info) const;
 
     /**
      *  If the shader subclass is composed of two shaders, return true, and if rec is not NULL,
      *  fill it out with info about the shader.
+     *
+     *  These are bare pointers; the ownership and reference count are unchanged.
      */
 
     struct ComposeRec {
         const SkShader*     fShaderA;
         const SkShader*     fShaderB;
         const SkXfermode*   fMode;
     };
 
     virtual bool asACompose(ComposeRec* rec) const { return false; }
 
@@ skipping 87 matching lines @@
      */
     virtual Context* onCreateContext(const ContextRec&, void* storage) const;
 
 private:
     SkMatrix fLocalMatrix;
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif