Un-nest configs in GN files.

People sometimes nest targets or configs, usually with the assumption that this limits the visibility of a config to within a target. But this nesting provides no visibility restrictions over declaring it outside of a block.

Un-nest for clarity.

Review URL: https://codereview.chromium.org/1318823008

Cr-Original-Commit-Position: refs/heads/master@{#346461}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4af2eac8e84692d94f88504ab6e0b244b88dddcb

BUILD.gn

@@ -28,6 +28,13 @@ static_library("zlib_x86_simd") {
   configs += [ "//build/config/compiler:no_chromium_code" ]
 }
 
+config("zlib_warnings") {
+  if (is_clang && !is_ios &&
+      (current_cpu == "x86" || current_cpu == "x64")) {
+    cflags = [ "-Wno-incompatible-pointer-types" ]
+  }
+}
+
 static_library("zlib") {
   if (!is_win) {
     # Don't stomp on "libzlib" on other platforms.
@@ -67,17 +74,13 @@ static_library("zlib") {
 
   if (!is_ios && (current_cpu == "x86" || current_cpu == "x64")) {
     sources += [ "x86.c" ]
-
-    config("zlib_warnings") {
-      if (is_clang) {
-        cflags = [ "-Wno-incompatible-pointer-types" ]
-      }
-    }
-    configs += [ ":zlib_warnings" ]
   }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [
+    ":zlib_warnings",
+    "//build/config/compiler:no_chromium_code",
+  ]
 
   public_configs = [ ":zlib_config" ]
   deps = [
@@ -85,6 +88,14 @@ static_library("zlib") {
   ]
 }
 
+config("minizip_warnings") {
+  visibility = [ ":*" ]
+  if (is_clang) {
+    # zlib uses `if ((a == b))` for some reason.
+    cflags = [ "-Wno-parentheses-equality" ]
+  }
+}
+
 static_library("minizip") {
   sources = [
     "contrib/minizip/ioapi.c",
@@ -113,13 +124,6 @@ static_library("minizip") {
     ":zlib",
   ]
 
-  config("minizip_warnings") {
-    if (is_clang) {
-      # zlib uses `if ((a == b))` for some reason.
-      cflags = [ "-Wno-parentheses-equality" ]
-    }
-  }
-
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   configs += [ ":minizip_warnings" ]