Fill incomplete images in SkCodec parent class

src/codec/SkSampler.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkSampler_DEFINED
 #define SkSampler_DEFINED
 
 #include "SkTypes.h"
 
 class SkSampler : public SkNoncopyable {
 public:
     /**
      *  Update the sampler to sample every sampleX'th pixel. Returns the
      *  width after sampling.
      */
     int setSampleX(int sampleX) {
         return this->onSetSampleX(sampleX);
     }
 
+    /**
+     * Fill the remainder of the destination with a single color
+     *
+     * @param info
+     * Contains the color type of the rows to fill.
+     * Contains the width of the destination rows to fill
+     * Contains the number of rows that we need to fill.
+     *
+     * @param dst
+     * The destination row to fill from.
+     *
+     * @param rowBytes
+     * Stride in bytes of the destination.
+     *
+     * @param colorOrIndex
+     * If colorType is kN32, colorOrIndex is treated as a 32-bit color.
+     * If colorType is k565, colorOrIndex is treated as a 16-bit color.
+     * If colorType is kGray, colorOrIndex is treated as an 8-bit color.
+     * If colorType is kIndex, colorOrIndex is treated as an 8-bit index.
+     * Other SkColorTypes are not supported.
+     *
+     * @param zeroInit
+     * Indicates whether memory is already zero initialized.
+     *
+     */
+    static void Fill(const SkImageInfo& info, void* dst, size_t rowBytes,
+            uint32_t colorOrIndex, SkCodec::ZeroInitialized zeroInit);
+
+    /**
+     * Allow subclasses to implement unique versions of fill().
+     */
+    virtual void fill(const SkImageInfo& info, void* dst, size_t rowBytes,
+            uint32_t colorOrIndex, SkCodec::ZeroInitialized zeroInit) {}
+
     virtual ~SkSampler() {}
 private:
+
     virtual int onSetSampleX(int) = 0;
 };
 
 #endif // SkSampler_DEFINED