Revert of Revert of Rename kPMColor_SkColorType to kN32_SkColorType.

src/effects/SkDisplacementMapEffect.cpp

Index: src/effects/SkDisplacementMapEffect.cpp
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 0200cabff85bf942a1b6d697d2e0370fd2672c6d..39222444d274b72934027224d29249e654b188f5 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -205,8 +205,8 @@
         (displInput && !displInput->filterImage(proxy, src, ctx, &displ, &displOffset))) {
         return false;
     }
-    if ((displ.colorType() != kPMColor_SkColorType) ||
-        (color.colorType() != kPMColor_SkColorType)) {
+    if ((displ.colorType() != kN32_SkColorType) ||
+        (color.colorType() != kN32_SkColorType)) {
         return false;
     }
     SkIRect bounds;