Delete reallyHasAlpha() from SkCodec

TBR=reed
BUG=skia:3582
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1557403002

Review URL: https://codereview.chromium.org/1557403002
diff --git a/src/codec/SkMaskSwizzler.cpp b/src/codec/SkMaskSwizzler.cpp
index e5facc1..01502cb 100644
--- a/src/codec/SkMaskSwizzler.cpp
+++ b/src/codec/SkMaskSwizzler.cpp
@@ -9,7 +9,7 @@
 #include "SkColorPriv.h"
 #include "SkMaskSwizzler.h"
 
-static SkSwizzler::ResultAlpha swizzle_mask16_to_n32_opaque(
+static void swizzle_mask16_to_n32_opaque(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
@@ -24,54 +24,47 @@
         dstPtr[i] = SkPackARGB32NoCheck(0xFF, red, green, blue);
         srcPtr += sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask16_to_n32_unpremul(
+static void swizzle_mask16_to_n32_unpremul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     uint16_t* srcPtr = ((uint16_t*) srcRow) + startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint16_t p = srcPtr[0];
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
         srcPtr += sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask16_to_n32_premul(
+static void swizzle_mask16_to_n32_premul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     uint16_t* srcPtr = ((uint16_t*) srcRow) + startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint16_t p = srcPtr[0];
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPreMultiplyARGB(alpha, red, green, blue);
         srcPtr += sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
 // TODO (msarett): We have promoted a two byte per pixel image to 8888, only to
 // convert it back to 565. Instead, we should swizzle to 565 directly.
-static SkSwizzler::ResultAlpha swizzle_mask16_to_565(
+static void swizzle_mask16_to_565(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
@@ -86,10 +79,9 @@
         dstPtr[i] = SkPack888ToRGB16(red, green, blue);
         srcPtr += sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask24_to_n32_opaque(
+static void swizzle_mask24_to_n32_opaque(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
@@ -104,52 +96,45 @@
         dstPtr[i] = SkPackARGB32NoCheck(0xFF, red, green, blue);
         srcRow += 3 * sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask24_to_n32_unpremul(
+static void swizzle_mask24_to_n32_unpremul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     srcRow += 3 * startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint32_t p = srcRow[0] | (srcRow[1] << 8) | srcRow[2] << 16;
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
         srcRow += 3 * sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask24_to_n32_premul(
+static void swizzle_mask24_to_n32_premul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     srcRow += 3 * startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint32_t p = srcRow[0] | (srcRow[1] << 8) | srcRow[2] << 16;
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPreMultiplyARGB(alpha, red, green, blue);
         srcRow += 3 * sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask24_to_565(
+static void swizzle_mask24_to_565(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
@@ -164,10 +149,9 @@
         dstPtr[i] = SkPack888ToRGB16(red, green, blue);
         srcRow += 3 * sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask32_to_n32_opaque(
+static void swizzle_mask32_to_n32_opaque(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
@@ -182,52 +166,45 @@
         dstPtr[i] = SkPackARGB32NoCheck(0xFF, red, green, blue);
         srcPtr += sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask32_to_n32_unpremul(
+static void swizzle_mask32_to_n32_unpremul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     uint32_t* srcPtr = ((uint32_t*) srcRow) + startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint32_t p = srcPtr[0];
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
         srcPtr += sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask32_to_n32_premul(
+static void swizzle_mask32_to_n32_premul(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
 
     // Use the masks to decode to the destination
     uint32_t* srcPtr = ((uint32_t*) srcRow) + startX;
     SkPMColor* dstPtr = (SkPMColor*) dstRow;
-    INIT_RESULT_ALPHA;
     for (int i = 0; i < width; i++) {
         uint32_t p = srcPtr[0];
         uint8_t red = masks->getRed(p);
         uint8_t green = masks->getGreen(p);
         uint8_t blue = masks->getBlue(p);
         uint8_t alpha = masks->getAlpha(p);
-        UPDATE_RESULT_ALPHA(alpha);
         dstPtr[i] = SkPreMultiplyARGB(alpha, red, green, blue);
         srcPtr += sampleX;
     }
-    return COMPUTE_RESULT_ALPHA;
 }
 
-static SkSwizzler::ResultAlpha swizzle_mask32_to_565(
+static void swizzle_mask32_to_565(
         void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks,
         uint32_t startX, uint32_t sampleX) {
     // Use the masks to decode to the destination
@@ -241,7 +218,6 @@
         dstPtr[i] = SkPack888ToRGB16(red, green, blue);
         srcPtr += sampleX;
     }
-    return SkSwizzler::kOpaque_ResultAlpha;
 }
 
 /*
@@ -394,7 +370,7 @@
  * Swizzle the specified row
  *
  */
-SkSwizzler::ResultAlpha SkMaskSwizzler::swizzle(void* dst, const uint8_t* SK_RESTRICT src) {
+void SkMaskSwizzler::swizzle(void* dst, const uint8_t* SK_RESTRICT src) {
     SkASSERT(nullptr != dst && nullptr != src);
-    return fRowProc(dst, src, fDstWidth, fMasks, fX0, fSampleX);
+    fRowProc(dst, src, fDstWidth, fMasks, fX0, fSampleX);
 }