Switch SkColorFilterImageFilter over to new onFilterImage interface

src/core/SkSpecialImage.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file
  */
 #include "SkSpecialImage.h"
 
 #if SK_SUPPORT_GPU
 #include "GrTexture.h"
@@ skipping 49 matching lines @@
     }
     if (GrTexture* peek = as_SIB(this)->peekTexture()) {
         return peek->getContext() == context ? sk_sp<SkSpecialImage>(SkRef(this)) : nullptr;
     }
 
     SkBitmap bmp;
     if (!this->internal_getBM(&bmp)) {
         return nullptr;
     }
 
+    if (bmp.empty()) {
+        return SkSpecialImage::MakeFromRaster(proxy, SkIRect::MakeEmpty(), bmp);
+    }
+
     SkAutoTUnref<GrTexture> resultTex(
         GrRefCachedBitmapTexture(context, bmp, GrTextureParams::ClampNoFilter()));
     if (!resultTex) {
         return nullptr;
     }
 
     SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
 
     return SkSpecialImage::MakeFromGpu(proxy,
                                        SkIRect::MakeWH(resultTex->width(), resultTex->height()),
@@ skipping 455 matching lines @@
 
 sk_sp<SkSpecialImage> SkSpecialImage::MakeFromGpu(SkImageFilter::Proxy* proxy,
                                                   const SkIRect& subset,
                                                   uint32_t uniqueID,
                                                   GrTexture* tex,
                                                   SkAlphaType at) {
     return nullptr;
 }
 
 #endif