remove unused SkBitmapFilter::Allocate

src/core/SkBitmapFilter.cpp

Index: src/core/SkBitmapFilter.cpp
diff --git a/src/core/SkBitmapFilter.cpp b/src/core/SkBitmapFilter.cpp
deleted file mode 100644
index d96a3854050c78456049a32d61070f5784cebe6c..0000000000000000000000000000000000000000
--- a/src/core/SkBitmapFilter.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * 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 "SkBitmapFilter.h"
-#include "SkRTConf.h"
-#include "SkTypes.h"
-
-#include <string.h>
-
-// These are the per-scanline callbacks that are used when we must resort to
-// resampling an image as it is blitted.  Typically these are used only when
-// the image is rotated or has some other complex transformation applied.
-// Scaled images will usually be rescaled directly before rasterization.
-
-SK_CONF_DECLARE(const char *, c_bitmapFilter, "bitmap.filter", "mitchell", "Which scanline bitmap filter to use [mitchell, lanczos, hamming, gaussian, triangle, box]");
-
-SkBitmapFilter *SkBitmapFilter::Allocate() {
-    if (!strcmp(c_bitmapFilter, "mitchell")) {
-        return new SkMitchellFilter;
-    } else if (!strcmp(c_bitmapFilter, "lanczos")) {
-        return new SkLanczosFilter;
-    } else if (!strcmp(c_bitmapFilter, "hamming")) {
-        return new SkHammingFilter;
-    } else if (!strcmp(c_bitmapFilter, "gaussian")) {
-        return new SkGaussianFilter(2);
-    } else if (!strcmp(c_bitmapFilter, "triangle")) {
-        return new SkTriangleFilter;
-    } else if (!strcmp(c_bitmapFilter, "box")) {
-        return new SkBoxFilter;
-    } else {
-        SkDEBUGFAIL("Unknown filter type");
-    }
-
-    return nullptr;
-}
-