change asABitmap to isABitmap on shader

src/core/SkShader.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 "SkAtomics.h"
 #include "SkBitmapProcShader.h"
 #include "SkColorShader.h"
@@ skipping 307 matching lines @@
 }
 
 void SkColorShader::ColorShaderContext::shadeSpan16(int x, int y, uint16_t span[], int count) {
     sk_memset16(span, fColor16, count);
 }
 
 void SkColorShader::ColorShaderContext::shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) {
     memset(alpha, SkGetPackedA32(fPMColor), count);
 }
 
-// if we had a asAColor method, that would be more efficient...
-SkShader::BitmapType SkColorShader::asABitmap(SkBitmap* bitmap, SkMatrix* matrix,
-                                              TileMode modes[]) const {
-    return kNone_BitmapType;
-}
-
 SkShader::GradientType SkColorShader::asAGradient(GradientInfo* info) const {
     if (info) {
         if (info->fColors && info->fColorCount >= 1) {
             info->fColors[0] = fColor;
         }
         info->fColorCount = 1;
         info->fTileMode = SkShader::kRepeat_TileMode;
     }
     return kColor_GradientType;
 }
@@ skipping 46 matching lines @@
 #include "SkEmptyShader.h"
 
 void SkEmptyShader::toString(SkString* str) const {
     str->append("SkEmptyShader: (");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif