[PoC] Reformat all BUILD.gn and *.gni files with new gn.

third_party/mesa/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ui.gni")
 
 config("mesa_headers_config") {
   include_dirs = [ "src/include" ]
   if (!use_x11) {
     defines = [ "MESA_EGL_NO_X11_HEADERS" ]
@@ skipping 702 matching lines @@
       configs -= [ "//build/config/clang:extra_warnings" ]
     }
 
     if (is_win) {
       ldflags =
           [ "/DEF:" + rebase_path("src/src/mesa/drivers/osmesa/osmesa.def",
                                   root_build_dir) ]
     }
 
     deps = [
+      ":mesa",
       ":mesa_headers",
-      ":mesa",
       ":mesa_libglslcommon",
       "//build/config/sanitizers:deps",
     ]
 
     if (is_win) {
       defines = [
         "BUILD_GL32",
         "KEYWORD1=GLAPI",
         "KEYWORD2=GLAPIENTRY",
       ]
     }
   }
 } else {
   #  Placeholder to allow targets to unconditionally depend on this.
   group("osmesa") {
   }
 }  # !is_android
 # TODO(GYP) Android osmesa_in_lib_dir target.