Reland kPMColor_SkColorType to kN32_SkColorType.

src/effects/SkLightingImageFilter.cpp

Index: src/effects/SkLightingImageFilter.cpp
diff --git a/src/effects/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index 09ceef03ef47b380a9bad2a3fcb65bfff8ff397f..b485ae1bb45d91ee7fbc44ea52e56f7ca705e0a7 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -943,7 +943,7 @@ bool SkDiffuseLightingImageFilter::onFilterImage(Proxy* proxy,
         return false;
     }
 
-    if (src.colorType() != kPMColor_SkColorType) {
+    if (src.colorType() != kN32_SkColorType) {
         return false;
     }
     SkIRect bounds;
@@ -1034,7 +1034,7 @@ bool SkSpecularLightingImageFilter::onFilterImage(Proxy* proxy,
         return false;
     }
 
-    if (src.colorType() != kPMColor_SkColorType) {
+    if (src.colorType() != kN32_SkColorType) {
         return false;
     }