diff --git a/src/enc/histogram.c b/src/enc/histogram.c
index e0379d54..6a35eda3 100644
--- a/src/enc/histogram.c
+++ b/src/enc/histogram.c
@@ -88,8 +88,7 @@ VP8LHistogramSet* VP8LAllocateHistogramSet(int size, int cache_bits) {
 // -----------------------------------------------------------------------------
 
 void VP8LConvertPopulationCountTableToBitEstimates(
-    int num_symbols, const int* const population_counts,
-    double* const output) {
+    int num_symbols, const int population_counts[], double output[]) {
   int sum = 0;
   int nonzeros = 0;
   int i;
@@ -206,9 +205,6 @@ double VP8LHistogramEstimateBitsBulk(const VP8LHistogram* const p) {
   return retval;
 }
 
-double VP8LHistogramEstimateBits(const VP8LHistogram* const p) {
-  return VP8LHistogramEstimateBitsHeader(p) + VP8LHistogramEstimateBitsBulk(p);
-}
 
 // Returns the cost encode the rle-encoded entropy code.
 // The constants in this function are experimental.
@@ -249,7 +245,8 @@ static double HuffmanCost(const int* const population, int length) {
   return retval;
 }
 
-double VP8LHistogramEstimateBitsHeader(const VP8LHistogram* const p) {
+// Estimates the Huffman dictionary + other block overhead size.
+static double HistogramEstimateBitsHeader(const VP8LHistogram* const p) {
   return HuffmanCost(&p->alpha_[0], 256) +
          HuffmanCost(&p->red_[0], 256) +
          HuffmanCost(&p->literal_[0], VP8LHistogramNumCodes(p)) +
@@ -257,6 +254,10 @@ double VP8LHistogramEstimateBitsHeader(const VP8LHistogram* const p) {
          HuffmanCost(&p->distance_[0], NUM_DISTANCE_CODES);
 }
 
+double VP8LHistogramEstimateBits(const VP8LHistogram* const p) {
+  return HistogramEstimateBitsHeader(p) + VP8LHistogramEstimateBitsBulk(p);
+}
+
 static void HistogramBuildImage(int xsize, int histo_bits,
                                 const VP8LBackwardRefs* const backward_refs,
                                 VP8LHistogramSet* const image) {
diff --git a/src/enc/histogram.h b/src/enc/histogram.h
index 931fd853..480aba81 100644
--- a/src/enc/histogram.h
+++ b/src/enc/histogram.h
@@ -76,10 +76,6 @@ void VP8LHistogramAddSinglePixOrCopy(VP8LHistogram* const histo,
 // approximately maps to.
 double VP8LHistogramEstimateBits(const VP8LHistogram* const p);
 
-// This function estimates the Huffman dictionary + other block overhead
-// size for creating a new deflate block.
-double VP8LHistogramEstimateBitsHeader(const VP8LHistogram* const p);
-
 // This function estimates the cost in bits excluding the bits needed to
 // represent the entropy code itself.
 double VP8LHistogramEstimateBitsBulk(const VP8LHistogram* const p);
@@ -100,34 +96,13 @@ static WEBP_INLINE void VP8LHistogramAdd(VP8LHistogram* const p,
   }
 }
 
-static WEBP_INLINE void VP8LHistogramRemove(VP8LHistogram* const p,
-                                            const VP8LHistogram* const a) {
-  int i;
-  for (i = 0; i < PIX_OR_COPY_CODES_MAX; ++i) {
-    p->literal_[i] -= a->literal_[i];
-    assert(p->literal_[i] >= 0);
-  }
-  for (i = 0; i < NUM_DISTANCE_CODES; ++i) {
-    p->distance_[i] -= a->distance_[i];
-    assert(p->distance_[i] >= 0);
-  }
-  for (i = 0; i < 256; ++i) {
-    p->red_[i] -= a->red_[i];
-    p->blue_[i] -= a->blue_[i];
-    p->alpha_[i] -= a->alpha_[i];
-    assert(p->red_[i] >= 0);
-    assert(p->blue_[i] >= 0);
-    assert(p->alpha_[i] >= 0);
-  }
-}
-
 static WEBP_INLINE int VP8LHistogramNumCodes(const VP8LHistogram* const p) {
   return 256 + NUM_LENGTH_CODES +
       ((p->palette_code_bits_ > 0) ? (1 << p->palette_code_bits_) : 0);
 }
 
 void VP8LConvertPopulationCountTableToBitEstimates(
-    int n, const int* const population_counts, double* const output);
+    int num_symbols, const int population_counts[], double output[]);
 
 // Builds the histogram image.
 int VP8LGetHistoImageSymbols(int xsize, int ysize,