Revert of Un-nest configs in GN files. (patchset #3 id:40001 of https://codereview.chromium.org/1318823008/ )

Reason for revert:
This breaks why these configs exist in the first place and seriously breaks the clang/win gn build (which is what these configs exist for).

Original issue's description:
> 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.
>
> Committed: https://crrev.com/4af2eac8e84692d94f88504ab6e0b244b88dddcb
> Cr-Commit-Position: refs/heads/master@{#346461}

TBR=dpranke@chromium.org,brettw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1316843006

Cr-Commit-Position: refs/heads/master@{#346695}

1 files changed, 9 insertions, 9 deletions

diff --git a/third_party/mesa/BUILD.gn b/third_party/mesa/BUILD.gn
index 58cb60c..052401f 100644
--- a/third_party/mesa/BUILD.gn
+++ b/third_party/mesa/BUILD.gn
@@ -148,15 +148,6 @@ config("mesa_internal_warnings") {
   }
 }
 
-config("mesa_libglslcommon_warnings") {
-  if (is_clang) {
-    cflags = [
-      # https://bugs.freedesktop.org/show_bug.cgi?id=91645:
-      "-Wno-overloaded-virtual",
-    ]
-  }
-}
-
 static_library("mesa_libglslcommon") {
   sources = [
     "$generated_src_dir/mesa/glcpp-lex.c",
@@ -261,6 +252,15 @@ static_library("mesa_libglslcommon") {
     "src/src/glsl/strtod.h",
   ]
 
+  config("mesa_libglslcommon_warnings") {
+    if (is_clang) {
+      cflags = [
+        # https://bugs.freedesktop.org/show_bug.cgi?id=91645:
+        "-Wno-overloaded-virtual",
+      ]
+    }
+  }
+
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   previous_configs = configs