Revert of Fix colorType/alphaType checks in SkCodec (patchset #5 id:80001 of https://codereview.chromium.org/1695473002/ )

Reason for revert:
Really bad images in Gold.

Original issue's description:
> Fix colorType/alphaType checks in SkCodec
>
> Make getPixels() and startScanlineDecode() behave
> consistently.
>
> Require that kGray8 decodes are opaque.
>
> Assert that creating the swizzler succeeds.
>
> BUG=skia:4203
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1695473002
>
> Committed: https://skia.googlesource.com/skia/+/c7578b6cdd03b61f076ffc7956efd952d6c301c0

TBR=scroggo@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4203

Review URL: https://codereview.chromium.org/1694023002

1 files changed, 17 insertions, 4 deletions

diff --git a/src/codec/SkBmpMaskCodec.cpp b/src/codec/SkBmpMaskCodec.cpp
index 21d231b15f..b603de9a03 100644
--- a/src/codec/SkBmpMaskCodec.cpp
+++ b/src/codec/SkBmpMaskCodec.cpp
@@ -57,12 +57,25 @@ SkCodec::Result SkBmpMaskCodec::onGetPixels(const SkImageInfo& dstInfo,
     return kSuccess;
 }
 
-SkCodec::Result SkBmpMaskCodec::prepareToDecode(const SkImageInfo& dstInfo,
-        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
-    // Initialize the mask swizzler
+bool SkBmpMaskCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& options) {
+    // Create the swizzler
     fMaskSwizzler.reset(SkMaskSwizzler::CreateMaskSwizzler(dstInfo, this->getInfo(), fMasks,
             this->bitsPerPixel(), options));
-    SkASSERT(fMaskSwizzler);
+
+    if (nullptr == fMaskSwizzler.get()) {
+        return false;
+    }
+
+    return true;
+}
+
+SkCodec::Result SkBmpMaskCodec::prepareToDecode(const SkImageInfo& dstInfo,
+        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
+    // Initialize a the mask swizzler
+    if (!this->initializeSwizzler(dstInfo, options)) {
+        SkCodecPrintf("Error: cannot initialize swizzler.\n");
+        return SkCodec::kInvalidConversion;
+    }
 
     return SkCodec::kSuccess;
 }