rm SkPreConfig.h and SkPostConfig.h

We treat them as part of SkTypes.h, so let's just merge them in?

Change-Id: Icd6db3913a679ceb9de09027d17eb9361754b016
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/268769
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Reed <reed@google.com>

Author: Mike Klein

gn/core.gni

@@ -65,8 +65,6 @@ skia_core_public = [
   "$_include/core/SkPngChunkReader.h",
   "$_include/core/SkPoint.h",
   "$_include/core/SkPoint3.h",
-  "$_include/core/SkPostConfig.h",
-  "$_include/core/SkPreConfig.h",
   "$_include/core/SkPromiseImageTexture.h",
   "$_include/core/SkRRect.h",
   "$_include/core/SkRSXform.h",

gn/gn_to_bp.py

@@ -464,7 +464,7 @@ def write_config(config_path, defines, platform):
   gn_to_bp_utils.WriteUserConfig(config_path, defines)
   append_to_file(config_path, '''
 // Correct SK_BUILD_FOR flags that may have been set by
-// SkPreConfig.h/Android.bp
+// SkTypes.h/Android.bp
 #ifndef SK_BUILD_FOR_%s
     #define SK_BUILD_FOR_%s
 #endif

include/config/SkUserConfig.h

@@ -10,19 +10,9 @@
 #ifndef SkUserConfig_DEFINED
 #define SkUserConfig_DEFINED
 
-/*  SkTypes.h, the root of the public header files, includes SkPreConfig.h,
-    then SkUserConfig.h, then SkPostConfig.h.
-
-    SkPreConfig.h runs first, and it is responsible for initializing certain
-    skia defines.
-
-    SkPostConfig.h runs last, and its job is to just check that the final
-    defines are consistent (i.e. that we don't have mutually conflicting
-    defines).
-
-    SkUserConfig.h (this file) runs in the middle. It gets to change or augment
-    the list of flags initially set in preconfig, and then postconfig checks
-    that everything still makes sense.
+/*  SkTypes.h, the root of the public header files, includes this file
+    SkUserConfig.h after first initializing certain Skia defines, letting
+    this file change or augment those flags.
 
     Below are optional defines that add, subtract, or change default behavior
     in Skia. Your port can locally edit this file to enable/disable flags as
@@ -39,7 +29,7 @@
     each 32bit pixel is in premultiplied form). This code can be very useful
     during development, but will slow things down in a shipping product.
 
-    By default, these mutually exclusive flags are defined in SkPreConfig.h,
+    By default, these mutually exclusive flags are defined in SkTypes.h,
     based on the presence or absence of NDEBUG, but that decision can be changed
     here.
  */