Changing name of has_transpareny_in_palette to has_transparency_in_tRNS

src/codec/SkCodec_libpng.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec_libpng.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 82 matching lines @@
         fPng_ptr = NULL;
         fInfo_ptr = NULL;
     }
 
 private:
     png_structp     fPng_ptr;
     png_infop       fInfo_ptr;
 };
 #define AutoCleanPng(...) SK_REQUIRE_LOCAL_VAR(AutoCleanPng)
 
-// call only if color_type is PALETTE. Returns true if the ctable has alpha
-static bool has_transparency_in_palette(png_structp png_ptr,
+//checks if there is transparency info in the tRNS chunk
+//image types which could have data in the tRNS chunk include: Index8, Gray8, RGB
+static bool has_transparency_in_tRNS(png_structp png_ptr,
                                         png_infop info_ptr) {
     if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
         return false;
     }
 
     png_bytep trans;
     int num_trans;
     png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, NULL);
     return num_trans > 0;
 }
@@ skipping 165 matching lines @@
     if (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8) {
         png_set_expand_gray_1_2_4_to_8(png_ptr);
     }
 
     // Now determine the default SkColorType and SkAlphaType and set required transforms
     SkColorType skColorType;
     SkAlphaType skAlphaType;
     switch (colorType) {
         case PNG_COLOR_TYPE_PALETTE:
             skColorType = kIndex_8_SkColorType;
-            skAlphaType = has_transparency_in_palette(png_ptr, info_ptr) ?
+            skAlphaType = has_transparency_in_tRNS(png_ptr, info_ptr) ?
                     kUnpremul_SkAlphaType : kOpaque_SkAlphaType;
             break;
         case PNG_COLOR_TYPE_RGB:
-            if (has_transparency_in_palette(png_ptr, info_ptr)) {
+            if (has_transparency_in_tRNS(png_ptr, info_ptr)) {
                 //convert to RGBA with tranparency information in tRNS chunk if it exists
                 png_set_tRNS_to_alpha(png_ptr);
                 skAlphaType = kUnpremul_SkAlphaType;
             } else {
                 //convert to RGBA with Opaque Alpha 
                 png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
                 skAlphaType = kOpaque_SkAlphaType;
             }
             skColorType = kN32_SkColorType;
             break;
         case PNG_COLOR_TYPE_GRAY:
-            if (has_transparency_in_palette(png_ptr, info_ptr)) {
+            if (has_transparency_in_tRNS(png_ptr, info_ptr)) {
                 //FIXME: support gray with alpha as a color type
                 //convert to RGBA if there is transparentcy info in the tRNS chunk
                 png_set_tRNS_to_alpha(png_ptr);
                 png_set_gray_to_rgb(png_ptr);
                 skColorType = kN32_SkColorType;
                 skAlphaType = kUnpremul_SkAlphaType;
             } else {
                 skColorType = kGray_8_SkColorType;
                 skAlphaType = kOpaque_SkAlphaType;
             }
@@ skipping 444 matching lines @@
 
     SkASSERT(fNumberPasses != INVALID_NUMBER_PASSES);
     if (fNumberPasses > 1) {
         // interlaced image
         return SkNEW_ARGS(SkPngInterlacedScanlineDecoder, (dstInfo, this));
     }
 
     return SkNEW_ARGS(SkPngScanlineDecoder, (dstInfo, this));
 }