Revert of Rename kPMColor_SkColorType to kN32_SkColorType. (https://codereview.chromium.org/227433009/)

Reason for revert:
breaking the Chrome deps roll.
http://build.chromium.org/p/chromium.linux/builders/Linux%20GN%20%28dbg%29/builds/839/steps/compile/logs/stdio

Original issue's description:
> Rename kPMColor_SkColorType to kN32_SkColorType.
>
> The new name better represents what this flag means.
>
> BUG=skia:2384
>
> Committed: http://code.google.com/p/skia/source/detail?r=14117

R=reed@google.com, scroggo@google.com
TBR=reed@google.com, scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:2384

Author: bensong@google.com

Review URL: https://codereview.chromium.org/234243002

git-svn-id: http://skia.googlecode.com/svn/trunk@14144 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/image/SkImagePriv.cpp b/src/image/SkImagePriv.cpp
index dada230..a044aad 100644
--- a/src/image/SkImagePriv.cpp
+++ b/src/image/SkImagePriv.cpp
@@ -20,7 +20,7 @@
         case kRGB_565_SkColorType:
             return SkBitmap::kRGB_565_Config;
 
-        case kN32_SkColorType:
+        case kPMColor_SkColorType:
             return SkBitmap::kARGB_8888_Config;
 
         case kIndex_8_SkColorType:
@@ -44,7 +44,7 @@
         kIndex_8_SkColorType,   // kIndex8_Config
         kRGB_565_SkColorType,   // kRGB_565_Config
         kARGB_4444_SkColorType, // kARGB_4444_Config
-        kN32_SkColorType,   // kARGB_8888_Config
+        kPMColor_SkColorType,   // kARGB_8888_Config
     };
     SkASSERT((unsigned)config < SK_ARRAY_COUNT(gCT));
     return gCT[config];