Revert of Make SkPngCodec decode progressively.

src/codec/SkSampler.h

Index: src/codec/SkSampler.h
diff --git a/src/codec/SkSampler.h b/src/codec/SkSampler.h
index af6f48598c36cdab720f792bb5dc7a7db3bd807e..73e11c986e2949981a4f215678582fdfce060e8c 100644
--- a/src/codec/SkSampler.h
+++ b/src/codec/SkSampler.h
@@ -18,30 +18,6 @@
      */
     int setSampleX(int sampleX) {
         return this->onSetSampleX(sampleX);
-    }
-
-    /**
-     *  Update the sampler to sample every sampleY'th row.
-     */
-    void setSampleY(int sampleY) {
-        fSampleY = sampleY;
-    }
-
-    /**
-     *  Retrieve the value set for sampleY.
-     */
-    int sampleY() const {
-        return fSampleY;
-    }
-
-    /**
-     *  Based on fSampleY, return whether this row belongs in the output.
-     *
-     *  @param row Row of the image, starting with the first row used in the
-     *      output.
-     */
-    bool rowNeeded(int row) const {
-        return row % fSampleY == 0;
     }
 
     /**
@@ -78,13 +54,8 @@
     virtual void fill(const SkImageInfo& info, void* dst, size_t rowBytes,
             uint32_t colorOrIndex, SkCodec::ZeroInitialized zeroInit) {}
 
-    SkSampler()
-        : fSampleY(1)
-    {}
-
     virtual ~SkSampler() {}
 private:
-    int fSampleY;
 
     virtual int onSetSampleX(int) = 0;
 };