Checking for valid colorType, alphaType, colorSpace in SkCodec

* Refactor to share code between SkPngCodec and SkWebpCodec
* Didn't end up sharing with SkJpegCodec but did refactor
  that code a bit
* Disallow conversions to F16 with non-linear color spaces
* Fail to decode if we fail to create a SkColorSpaceXform
  (should be an assert soon).  We used to fallback on a
  legacy decode if we failed to create the transform.
* A bunch of name changes

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2319293003

Committed: https://skia.googlesource.com/skia/+/7a9900d6d34e437bb24beb5524a1f6488ae138c9
Review-Url: https://codereview.chromium.org/2319293003
diff --git a/src/android/SkBitmapRegionCodec.cpp b/src/android/SkBitmapRegionCodec.cpp
index 9c21484..df0a32c 100644
--- a/src/android/SkBitmapRegionCodec.cpp
+++ b/src/android/SkBitmapRegionCodec.cpp
@@ -135,5 +135,8 @@
 }
 
 bool SkBitmapRegionCodec::conversionSupported(SkColorType colorType) {
-    return conversion_possible(fCodec->getInfo().makeColorType(colorType), fCodec->getInfo());
+    // Enable legacy behavior.
+    sk_sp<SkColorSpace> colorSpace = nullptr;
+    SkImageInfo dstInfo = fCodec->getInfo().makeColorType(colorType).makeColorSpace(colorSpace);
+    return conversion_possible_ignore_color_space(dstInfo, fCodec->getInfo());
 }