Remove many unused files from //skia/ext

skia/ext/recursive_gaussian_convolution.h

-// Copyright (c) 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef SKIA_EXT_RECURSIVE_GAUSSIAN_CONVOLUTION_H_
-#define SKIA_EXT_RECURSIVE_GAUSSIAN_CONVOLUTION_H_
-
-#include "skia/ext/convolver.h"
-#include "third_party/skia/include/core/SkSize.h"
-#include "third_party/skia/include/core/SkTypes.h"
-
-namespace skia {
-
-// RecursiveFilter, paired with SingleChannelRecursiveGaussianX and
-// SingleChannelRecursiveGaussianY routines below implement recursive filters as
-// described in 'Recursive implementation of the Gaussian filter' (Young, Vliet)
-// (1995). Single-letter variable names mirror exactly the usage in the paper to
-// ease reading and analysis.
-class RecursiveFilter {
- public:
-  enum Order {
-    FUNCTION,
-    FIRST_DERIVATIVE,
-    SECOND_DERIVATIVE
-  };
-
-  static float qFromSigma(float sigma);
-  static void computeCoefficients(float q, float b[4]);
-  SK_API RecursiveFilter(float sigma, Order order);
-
-  Order order() const { return order_; }
-  const float* b() const { return b_; }
-
- private:
-  Order order_;
-  float q_;
-  float b_[4];
-};
-
-// Applies a gaussian recursive filter given as |filter| to a single channel at
-// |input_channel_index| to image given in |source_data| along X axis.
-// The output is placed into |output| into channel |output_channel_index|.
-SK_API unsigned char SingleChannelRecursiveGaussianX(
-    const unsigned char* source_data,
-    int source_byte_row_stride,
-    int input_channel_index,
-    int input_channel_count,
-    const RecursiveFilter& filter,
-    const SkISize& image_size,
-    unsigned char* output,
-    int output_byte_row_stride,
-    int output_channel_index,
-    int output_channel_count,
-    bool absolute_values);
-
-// Applies a gaussian recursive filter along Y axis.
-SK_API unsigned char  SingleChannelRecursiveGaussianY(
-    const unsigned char* source_data,
-    int source_byte_row_stride,
-    int input_channel_index,
-    int input_channel_count,
-    const RecursiveFilter& filter,
-    const SkISize& image_size,
-    unsigned char* output,
-    int output_byte_row_stride,
-    int output_channel_index,
-    int output_channel_count,
-    bool absolute_values);
-}  // namespace skia
-
-#endif  // SKIA_EXT_RECURSIVE_GAUSSIAN_CONVOLUTION_H_