Create .mojo applications in a common subdir under out/Debug

mojo/public/mojo_application_manifest.gni

 # Copyright 2016 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("//mojo/public/mojo_constants.gni")
+
 # Used to produce a Mojo Application Manifest for an application.
 #
 # Parameters:
 #
 #   source
 #       The manifest file template for this application, must be valid JSON with
 #       a valid 'url' key matching application_name.
 #
 #   application_name
 #       The host portion of the mojo: URL of the application. The script
@@ skipping 45 matching lines @@
     if (defined(invoker.type)) {
       type = invoker.type
     }
 
     application_name = invoker.application_name
     inputs = [
       invoker.source,
     ]
 
     if (type == "mojo") {
-      output = "$root_out_dir/$application_name/manifest.json"
+      output = "$root_out_dir/$mojo_application_subdir/$application_name/manifest.json"
     } else {
       output = "$root_out_dir/${application_name}_manifest.json"
     }
     outputs = [
       output,
     ]
 
     rebase_parent = rebase_path(invoker.source, root_build_dir)
     rebase_output = rebase_path(output, root_build_dir)
 
     args = [
       "--application-name=$application_name",
       "--parent=$rebase_parent",
       "--output=$rebase_output",
     ]
 
     if (defined(invoker.packaged_applications)) {
       foreach(application_name, invoker.packaged_applications) {
-        input = "$root_out_dir/$application_name/manifest.json"
+        input = "$root_out_dir/$mojo_application_subdir/$application_name/manifest.json"
         inputs += [ input ]
         args += [ rebase_path(input, root_build_dir) ]
       }
     }
     deps = []
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
   }
 
   all_deps = []
   if (defined(invoker.deps)) {
     all_deps += invoker.deps
   }
 
   group("${target_name}__is_mojo_application_manifest") {
   }
 
   # Explicitly ensure that all dependencies are mojo_application_manifest
   # targets themselves.
   group("${target_name}__check_deps_are_all_mojo_application_manifest") {
     deps = []
     foreach(d, all_deps) {
       name = get_label_info(d, "label_no_toolchain")
       toolchain = get_label_info(d, "toolchain")
       deps += [ "${name}__is_mojo_application_manifest(${toolchain})" ]
     }
   }
 }