bitmapshader with A8 bitmap should be colorized by the paint's color

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 327 matching lines @@
      *  the paint.
      *
      *  @param src  The bitmap to use inside the shader
      *  @param tmx  The tiling mode to use when sampling the bitmap in the x-direction.
      *  @param tmy  The tiling mode to use when sampling the bitmap in the y-direction.
      *  @return     Returns a new shader object. Note: this function never returns null.
     */
     static SkShader* CreateBitmapShader(const SkBitmap& src,
                                         TileMode tmx, TileMode tmy);
 
+    virtual SkBitmap* getBitmap() { return NULL;}

[bsalomon, 2014/03/13 14:59:04]

I don't think the Shader should expose a bitmap. If there isn't a way to deduce
this behavior from the Shader already then maybe the Shader subclass should have
explicit control of what part of the SkPaint's color it wants to use.

[yunchao, 2014/03/13 15:05:12]

What about expose an interface like this: bool isA8BitmapShader()? 

[yunchao, 2014/03/13 15:32:28]

Do you think it is unsafe if the shader expose a bitmap? I think check the
shader's bitmap config in skPaint2GrPaint() is appropriate. 

+
     SkDEVCODE(virtual void toString(SkString* str) const;)
 
     SK_DEFINE_FLATTENABLE_TYPE(SkShader)
 
 protected:
     enum MatrixClass {
         kLinear_MatrixClass,            // no perspective
         kFixedStepInX_MatrixClass,      // fast perspective, need to call fixedStepInX() each scanline
         kPerspective_MatrixClass        // slow perspective, need to mappoints each pixel
     };
@@ skipping 10 matching lines @@
     SkMatrix            fLocalMatrix;
     SkMatrix            fTotalInverse;
     uint8_t             fPaintAlpha;
     uint8_t             fTotalInverseClass;
     SkDEBUGCODE(SkBool8 fInSetContext;)
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif