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

mandoline/BUILD.gn

 # Copyright 2015 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")
 
 group("all") {
   # Meta-target, don't link into production code.
   testonly = true
 
   deps = [
+    ":tests",
     "//mojo",
-    ":tests",
   ]
 
   if (is_android) {
     deps += [ "//mandoline/app/android" ]
   } else {
     deps += [
       "//components/mus/example",
       "//mandoline/app/desktop",
     ]
   }
@@ skipping 27 matching lines @@
       "//components/web_view/test_runner",
       "//media/mojo/services:tests",
       "//sql/mojo:apptests",
     ]
 
     if (use_aura) {
       deps += [ "//mandoline/ui/desktop_ui:mandoline_browser_apptests" ]
     }
   }
 }