remove dead methods now that we use specials exclusively for imagefilters

src/core/SkBitmapDevice.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkConfig8888.h"
 #include "SkDraw.h"
@@ skipping 346 matching lines @@
                                   const SkPoint verts[], const SkPoint textures[],
                                   const SkColor colors[], SkXfermode* xmode,
                                   const uint16_t indices[], int indexCount,
                                   const SkPaint& paint) {
     draw.drawVertices(vmode, vertexCount, verts, textures, colors, xmode,
                       indices, indexCount, paint);
 }
 
 void SkBitmapDevice::drawDevice(const SkDraw& draw, SkBaseDevice* device,
                                 int x, int y, const SkPaint& paint) {
+    SkASSERT(!paint.getImageFilter());
     draw.drawSprite(static_cast<SkBitmapDevice*>(device)->fBitmap, x, y, paint);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkBitmapDevice::drawSpecial(const SkDraw& draw, SkSpecialImage* srcImg, int x, int y,
                                  const SkPaint& paint) {
     SkASSERT(!srcImg->isTextureBacked());
 
     SkBitmap resultBM;
@@ skipping 54 matching lines @@
         paint.getRasterizer() ||
         paint.getPathEffect() ||
         paint.isFakeBoldText() ||
         paint.getStyle() != SkPaint::kFill_Style ||
         !SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode))
     {
         return true;
     }
     return false;
 }