Revert of Revert of Rename kPMColor_SkColorType to kN32_SkColorType.

src/ports/SkImageDecoder_CG.cpp

Index: src/ports/SkImageDecoder_CG.cpp
diff --git a/src/ports/SkImageDecoder_CG.cpp b/src/ports/SkImageDecoder_CG.cpp
index c61ce98a8bc50096ad7a5a4a44913bfe55a4df8c..c683752fdd5e4cf9026ab07260f6a112601f071d 100644
--- a/src/ports/SkImageDecoder_CG.cpp
+++ b/src/ports/SkImageDecoder_CG.cpp
@@ -209,7 +209,7 @@
             // <Error>: CGImageDestinationFinalize image destination does not have enough images
             // So instead we copy to 8888.
             if (bm.colorType() == kARGB_4444_SkColorType) {
-                bm.copyTo(&bitmap8888, kPMColor_SkColorType);
+                bm.copyTo(&bitmap8888, kN32_SkColorType);
                 bmPtr = &bitmap8888;
             }
             type = kUTTypePNG;