Enable legacy premuls in SkColorSpaceXform

***Will allow for simplified Android framework code, they typically
   want a color correct transform followed by a gamma encoded premul.
***Chrome does the same, so this will make it easier to replace their
   codecs.
***Will decrease code size.  Both types of premuls are moved off the
   fast path here - one is essentially unused in production and the
   other is not "encouraged".
***Will actually make the common case faster: sRGB->sRGB means no
   color xform, just premul in SkSwizzler.

BUG=skia:

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Change-Id: Ia4ec1d273b6f137151f951d37c0ebf975f6b9a3e
Reviewed-on: https://skia-review.googlesource.com/8848
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index c31d533..e9eeb45 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -474,17 +474,7 @@
     }
 }
 
-bool SkCodec::initializeColorXform(const SkImageInfo& info) {
-    // TODO (msarett):
-    // Handle equality checking and legacy behavior for flagged SkColorSpaces.
-    // Until this is implemented, remove any flags on output color spaces.  This
-    // will prevent strange behaviors.  Ex: sRGB != sRGB + flag, but we don't want
-    // this to trigger a color xform.
-    SkImageInfo dstInfo = info;
-    if (dstInfo.colorSpace()) {
-        dstInfo = info.makeColorSpace(as_CSB(dstInfo.colorSpace())->makeWithoutFlags());
-    }
-
+bool SkCodec::initializeColorXform(const SkImageInfo& dstInfo) {
     fColorXform = nullptr;
     bool needsPremul = needs_premul(dstInfo, fEncodedInfo);
     if (needs_color_xform(dstInfo, fSrcInfo, needsPremul)) {