Standardize naming on CoverageAsAlpha (rather than AlphaAsCoverage)

Also fix a spelling mistake: Coveage -> Coverage

Bug: skia:
Change-Id: I296415ca194b0805470596d297e1d815f43b404a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/201394
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/effects/GrCustomXfermode.cpp b/src/gpu/effects/GrCustomXfermode.cpp
index f69f25a..ce0d355 100644
--- a/src/gpu/effects/GrCustomXfermode.cpp
+++ b/src/gpu/effects/GrCustomXfermode.cpp
@@ -355,13 +355,13 @@
     */
     if (can_use_hw_blend_equation(fHWBlendEquation, coverage, caps)) {
         if (caps.blendEquationSupport() == GrCaps::kAdvancedCoherent_BlendEquationSupport) {
-            return AnalysisProperties::kCompatibleWithAlphaAsCoverage;
+            return AnalysisProperties::kCompatibleWithCoverageAsAlpha;
         } else {
-            return AnalysisProperties::kCompatibleWithAlphaAsCoverage |
+            return AnalysisProperties::kCompatibleWithCoverageAsAlpha |
                    AnalysisProperties::kRequiresNonOverlappingDraws;
         }
     }
-    return AnalysisProperties::kCompatibleWithAlphaAsCoverage |
+    return AnalysisProperties::kCompatibleWithCoverageAsAlpha |
            AnalysisProperties::kReadsDstInShader;
 }