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

Reason for revert:
Chrome's side of define changes not easy to figure out quickly. Reverting this for DEPS roll for now.

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/234833003

git-svn-id: http://skia.googlecode.com/svn/trunk@14149 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/tilemodes.cpp b/gm/tilemodes.cpp
index abecada..5b97f13 100644
--- a/gm/tilemodes.cpp
+++ b/gm/tilemodes.cpp
@@ -50,7 +50,7 @@
 }
 
 static const SkColorType gColorTypes[] = {
-    kN32_SkColorType,
+    kPMColor_SkColorType,
     kRGB_565_SkColorType,
 };
 
@@ -166,7 +166,7 @@
 
 static SkShader* make_bm(SkShader::TileMode tx, SkShader::TileMode ty) {
     SkBitmap bm;
-    makebm(&bm, kN32_SkColorType, gWidth, gHeight);
+    makebm(&bm, kPMColor_SkColorType, gWidth, gHeight);
     return SkShader::CreateBitmapShader(bm, tx, ty);
 }