Delay half-float vertex color determination until Op::finalize

Bug: skia:8871
Change-Id: I873e80e2d97a32e4524c177a9b6e07b0566a02ce
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/201682
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/gpu/SkGpuDevice_drawTexture.cpp b/src/gpu/SkGpuDevice_drawTexture.cpp
index 8c280d5..97f043f 100644
--- a/src/gpu/SkGpuDevice_drawTexture.cpp
+++ b/src/gpu/SkGpuDevice_drawTexture.cpp
@@ -209,7 +209,7 @@
     }
     SkPMColor4f color;
     if (GrPixelConfigIsAlphaOnly(proxy->config())) {
-        color = SkColor4fPrepForDst(paint.getColor4f(), dstInfo, *rtc->caps()).premul();
+        color = SkColor4fPrepForDst(paint.getColor4f(), dstInfo).premul();
     } else {
         float paintAlpha = paint.getColor4f().fA;
         color = { paintAlpha, paintAlpha, paintAlpha, paintAlpha };