Revert of Revert of Rename kPMColor_SkColorType to kN32_SkColorType. (https://codereview.chromium.org/234243002/)

Reason for revert:
Want to reland the original CL.

Original issue's description:
> 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
>
> TBR=reed@google.com,scroggo@google.com
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:2384
>
> Committed: http://code.google.com/p/skia/source/detail?r=14144

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

Author: scroggo@google.com

Review URL: https://codereview.chromium.org/235523003

git-svn-id: http://skia.googlecode.com/svn/trunk@14156 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkImageInfo.h b/include/core/SkImageInfo.h
index 1c73d95..8391954 100644
--- a/include/core/SkImageInfo.h
+++ b/include/core/SkImageInfo.h
@@ -80,12 +80,16 @@
     kLastEnum_SkColorType = kIndex_8_SkColorType,
 
 #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
-    kPMColor_SkColorType = kBGRA_8888_SkColorType
+    kN32_SkColorType = kBGRA_8888_SkColorType,
 #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
-    kPMColor_SkColorType = kRGBA_8888_SkColorType
+    kN32_SkColorType = kRGBA_8888_SkColorType,
 #else
 #error "SK_*32_SHFIT values must correspond to BGRA or RGBA byte order"
 #endif
+
+#ifdef SK_SUPPORT_LEGACY_N32_NAME
+    kPMColor_SkColorType = kN32_SkColorType
+#endif
 };
 
 static int SkColorTypeBytesPerPixel(SkColorType ct) {
@@ -136,7 +140,7 @@
      */
     static SkImageInfo MakeN32(int width, int height, SkAlphaType at) {
         SkImageInfo info = {
-            width, height, kPMColor_SkColorType, at
+            width, height, kN32_SkColorType, at
         };
         return info;
     }
@@ -146,7 +150,7 @@
      */
     static SkImageInfo MakeN32Premul(int width, int height) {
         SkImageInfo info = {
-            width, height, kPMColor_SkColorType, kPremul_SkAlphaType
+            width, height, kN32_SkColorType, kPremul_SkAlphaType
         };
         return info;
     }