Cache dst LUTs in SkColorSpaceXform

This is only useful in the rare case that the dst does not
fall into one of our main paths.

But it's a good optimization, since this does happen,
and typically, the dst won't change.

ColorCodecBench z620 --nonstd --xform_only
Without Patch 511us
With Patch    348us

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3400

Change-Id: Ibf68d9ce7072680465662922f4aa15630545e3d6
Reviewed-on: https://skia-review.googlesource.com/3400
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 1 insertions, 7 deletions

diff --git a/include/core/SkColorSpaceXform.h b/include/core/SkColorSpaceXform.h
index 15b3d49ee4..b1ca92ef55 100644
--- a/include/core/SkColorSpaceXform.h
+++ b/include/core/SkColorSpaceXform.h
@@ -50,17 +50,11 @@ public:
      *
      */
     bool apply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src, int count,
-               SkAlphaType alphaType) const {
-        return this->onApply(dstFormat, dst, srcFormat, src, count, alphaType);
-    }
-
+               SkAlphaType alphaType) const;
 
     virtual ~SkColorSpaceXform() {}
 
 protected:
-    virtual bool onApply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src,
-                         int count, SkAlphaType alphaType) const = 0;
-
     SkColorSpaceXform() {}
 };