Use the mojo::shell namespace consistently underly shell/.

shell/application_manager/fetcher.h

Index: shell/application_manager/fetcher.h
diff --git a/shell/application_manager/fetcher.h b/shell/application_manager/fetcher.h
index b9e9de5b830d7fdc56d81d1c20cf65aa24092b8a..23519cb0c5457f2c5e2773ee5bb245c1343d8896 100644
--- a/shell/application_manager/fetcher.h
+++ b/shell/application_manager/fetcher.h
@@ -13,12 +13,12 @@
 class GURL;
 
 namespace base {
-
 class FilePath;
 class TaskRunner;
 }
 
 namespace mojo {
+namespace shell {
 
 // Fetcher abstracts getting an application by either file or http[s] URL.
 //
@@ -70,6 +70,7 @@ class Fetcher {
   FetchCallback loader_callback_;
 };
 
+}  // namespace shell
 }  // namespace mojo
 
 #endif  // SHELL_APPLICATION_MANAGER_FETCHER_H_