mojom: Remove braces from module statements and make them come first.

mojo/shell/app_child_process.mojom

Index: mojo/shell/app_child_process.mojom
diff --git a/mojo/shell/app_child_process.mojom b/mojo/shell/app_child_process.mojom
index d8cef1200a2eb28f00d5d9b6ea5593a506735847..a0d72ca6c4ad02ad6a8f5abfa903b93fa5796385 100644
--- a/mojo/shell/app_child_process.mojom
+++ b/mojo/shell/app_child_process.mojom
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-module mojo.shell {
+module mojo.shell;
 
 [Client=AppChildControllerClient]
 interface AppChildController {
@@ -13,5 +13,3 @@ interface AppChildController {
 interface AppChildControllerClient {
   AppCompleted(int32 result);
 };
-
-}  // module mojo.shell