Checking for valid colorType, alphaType, colorSpace in SkCodec

src/codec/SkPngCodec.cpp

Index: src/codec/SkPngCodec.cpp
diff --git a/src/codec/SkPngCodec.cpp b/src/codec/SkPngCodec.cpp
index ac7238d3e904f284ac182fc769a90c1166946b6f..db4819147d0a47b8a89aec8f1cb9c4d94d1832be 100644
--- a/src/codec/SkPngCodec.cpp
+++ b/src/codec/SkPngCodec.cpp
@@ -357,25 +357,6 @@ static int bytes_per_pixel(int bitsPerPixel) {
     return bitsPerPixel / 8;
 }
 
-static bool png_conversion_possible(const SkImageInfo& dst, const SkImageInfo& src) {
-    // Ensure the alpha type is valid
-    if (!valid_alpha(dst.alphaType(), src.alphaType())) {
-        return false;
-    }
-
-    // Check for supported color types
-    switch (dst.colorType()) {
-        case kRGBA_8888_SkColorType:
-        case kBGRA_8888_SkColorType:
-        case kRGBA_F16_SkColorType:
-            return true;
-        case kRGB_565_SkColorType:
-            return kOpaque_SkAlphaType == src.alphaType();
-        default:
-            return dst.colorType() == src.colorType();
-    }
-}
-
 void SkPngCodec::allocateStorage(const SkImageInfo& dstInfo) {
     switch (fXformMode) {
         case kSwizzleOnly_XformMode:
@@ -422,7 +403,7 @@ public:
 
     Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& options,
             SkPMColor ctable[], int* ctableCount) override {
-        if (!png_conversion_possible(dstInfo, this->getInfo()) ||
+        if (!conversion_possible(dstInfo, this->getInfo()) ||
             !this->initializeXforms(dstInfo, options, ctable, ctableCount))
         {
             return kInvalidConversion;
@@ -489,7 +470,7 @@ public:
 
     Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& options,
             SkPMColor ctable[], int* ctableCount) override {
-        if (!png_conversion_possible(dstInfo, this->getInfo()) ||
+        if (!conversion_possible(dstInfo, this->getInfo()) ||
             !this->initializeXforms(dstInfo, options, ctable, ctableCount))
         {
             return kInvalidConversion;
@@ -809,16 +790,11 @@ bool SkPngCodec::initializeXforms(const SkImageInfo& dstInfo, const Options& opt
 
     bool needsColorXform = needs_color_xform(dstInfo, this->getInfo());
     if (needsColorXform) {
-        if (kGray_8_SkColorType == dstInfo.colorType() ||
-            kRGB_565_SkColorType == dstInfo.colorType())
-        {
-            return false;
-        }
-
         fColorXform = SkColorSpaceXform::New(sk_ref_sp(this->getInfo().colorSpace()),
                                              sk_ref_sp(dstInfo.colorSpace()));
 
-        if (!fColorXform && kRGBA_F16_SkColorType == dstInfo.colorType()) {
+        // TODO (msarett): Possibly working toward asserting this?
+        if (!fColorXform) {
             return false;
         }
     }
@@ -907,7 +883,7 @@ SkCodec::Result SkPngCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst,
                                         size_t rowBytes, const Options& options,
                                         SkPMColor ctable[], int* ctableCount,
                                         int* rowsDecoded) {
-    if (!png_conversion_possible(dstInfo, this->getInfo()) ||
+    if (!conversion_possible(dstInfo, this->getInfo()) ||
         !this->initializeXforms(dstInfo, options, ctable, ctableCount))
     {
         return kInvalidConversion;