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, 13 insertions, 5 deletions

diff --git a/src/codec/SkBmpStandardCodec.cpp b/src/codec/SkBmpStandardCodec.cpp
index 39d357be8b..47b10701d3 100644
--- a/src/codec/SkBmpStandardCodec.cpp
+++ b/src/codec/SkBmpStandardCodec.cpp
@@ -152,9 +152,9 @@ SkCodec::Result SkBmpStandardCodec::onGetPixels(const SkImageInfo& dstInfo,
     return true;
 }
 
-void SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts) {
+bool SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts) {
     // Get swizzler configuration
-    SkSwizzler::SrcConfig config = SkSwizzler::kUnknown;
+    SkSwizzler::SrcConfig config;
     switch (this->bitsPerPixel()) {
         case 1:
             config = SkSwizzler::kIndex1;
@@ -180,6 +180,7 @@ void SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Op
             break;
         default:
             SkASSERT(false);
+            return false;
     }
 
     // Get a pointer to the color table if it exists
@@ -187,7 +188,11 @@ void SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Op
 
     // Create swizzler
     fSwizzler.reset(SkSwizzler::CreateSwizzler(config, colorPtr, dstInfo, opts));
-    SkASSERT(fSwizzler);
+
+    if (nullptr == fSwizzler.get()) {
+        return false;
+    }
+    return true;
 }
 
 SkCodec::Result SkBmpStandardCodec::prepareToDecode(const SkImageInfo& dstInfo,
@@ -202,8 +207,11 @@ SkCodec::Result SkBmpStandardCodec::prepareToDecode(const SkImageInfo& dstInfo,
     // Copy the color table to the client if necessary
     copy_color_table(dstInfo, this->fColorTable, inputColorPtr, inputColorCount);
 
-    // Initialize a swizzler
-    this->initializeSwizzler(dstInfo, options);
+    // Initialize a swizzler if necessary
+    if (!this->initializeSwizzler(dstInfo, options)) {
+        SkCodecPrintf("Error: cannot initialize swizzler.\n");
+        return SkCodec::kInvalidConversion;
+    }
     return SkCodec::kSuccess;
 }