Revert of Checking for valid colorType, alphaType, colorSpace in SkCodec

src/codec/SkWebpCodec.cpp

Index: src/codec/SkWebpCodec.cpp
diff --git a/src/codec/SkWebpCodec.cpp b/src/codec/SkWebpCodec.cpp
index e8b27b2178fa98b76fa7afd6cf629e1366171632..0c3aa402bd70bfd2659b01d8468d4cfa252be82a 100644
--- a/src/codec/SkWebpCodec.cpp
+++ b/src/codec/SkWebpCodec.cpp
@@ -144,6 +144,25 @@
                            streamDeleter.release(), demux.release(), std::move(data));
 }
 
+static bool webp_conversion_possible(const SkImageInfo& dst, const SkImageInfo& src,
+                                     SkColorSpaceXform* colorXform) {
+    if (!valid_alpha(dst.alphaType(), src.alphaType())) {
+        return false;
+    }
+
+    switch (dst.colorType()) {
+        case kRGBA_F16_SkColorType:
+            return nullptr != colorXform;
+        case kBGRA_8888_SkColorType:
+        case kRGBA_8888_SkColorType:
+            return true;
+        case kRGB_565_SkColorType:
+            return nullptr == colorXform && src.alphaType() == kOpaque_SkAlphaType;
+        default:
+            return false;
+    }
+}
+
 SkISize SkWebpCodec::onGetScaledDimensions(float desiredScale) const {
     SkISize dim = this->getInfo().dimensions();
     // SkCodec treats zero dimensional images as errors, so the minimum size
@@ -193,15 +212,15 @@
 SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
                                          const Options& options, SkPMColor*, int*,
                                          int* rowsDecodedPtr) {
-    if (!conversion_possible(dstInfo, this->getInfo())) {
-        return kInvalidConversion;
-    }
 
     std::unique_ptr<SkColorSpaceXform> colorXform = nullptr;
     if (needs_color_xform(dstInfo, this->getInfo())) {
         colorXform = SkColorSpaceXform::New(sk_ref_sp(this->getInfo().colorSpace()),
                                             sk_ref_sp(dstInfo.colorSpace()));
-        SkASSERT(colorXform);
+    }
+
+    if (!webp_conversion_possible(dstInfo, this->getInfo(), colorXform.get())) {
+        return kInvalidConversion;
     }
 
     WebPDecoderConfig config;