Refactors building the system menu model into a common place

ui/views/views.gyp

Index: ui/views/views.gyp
diff --git a/ui/views/views.gyp b/ui/views/views.gyp
index 68791121095ffe5567f3f0d7a33b2ffd1d00c35b..a7c38b4c05b1c7a073ef73ca9a41f0df992dcdd8 100644
--- a/ui/views/views.gyp
+++ b/ui/views/views.gyp
@@ -448,9 +448,6 @@
       ],
       'conditions': [
         ['use_aura==1', {
-          'sources/': [
-            ['exclude', 'controls/menu/menu_2.*'],
-          ],
           'sources!': [
             'controls/native_control.cc',
             'controls/native_control.h',
@@ -476,12 +473,19 @@
             }],
             ['OS=="win"', {
               'sources/': [
+                ['include', 'controls/menu/native_menu_win.cc'],
+                ['include', 'controls/menu/native_menu_win.h'],
                 ['include', 'widget/desktop_aura/desktop_screen_win.cc'],
                 ['include', 'widget/desktop_aura/desktop_drag_drop_client_win.cc'],
                 ['include', 'widget/desktop_aura/desktop_drop_target_win.cc'],
                 ['include', 'widget/desktop_aura/desktop_root_window_host_win.cc'],
               ],
             }],
+            ['OS!="win"', {
+              'sources/': [
+                ['exclude', 'controls/menu/menu_2.*'],
+              ],
+            }],
           ],
         }],
         ['use_aura==0', {