platform-window: Add a PlatformWindowFactory for creating windows.

mojo/mojo_services.gypi

Index: mojo/mojo_services.gypi
diff --git a/mojo/mojo_services.gypi b/mojo/mojo_services.gypi
index 44e522ccd75bb2d8cc49d603635dfaa981746d45..e0940114ae8ecebef64bd9a4311119ff9caeb05e 100644
--- a/mojo/mojo_services.gypi
+++ b/mojo/mojo_services.gypi
@@ -304,12 +304,11 @@
         'services/native_viewport/native_viewport.h',
         'services/native_viewport/native_viewport_android.cc',
         'services/native_viewport/native_viewport_mac.mm',
-        'services/native_viewport/native_viewport_ozone.cc',
         'services/native_viewport/native_viewport_service.cc',
         'services/native_viewport/native_viewport_service.h',
         'services/native_viewport/native_viewport_stub.cc',
         'services/native_viewport/native_viewport_win.cc',
-        'services/native_viewport/native_viewport_x11.cc',
+        'services/native_viewport/platform_viewport.cc',
       ],
       'conditions': [
         ['OS=="win" or OS=="android" or OS=="linux" or OS=="mac"', {
@@ -322,6 +321,15 @@
             'mojo_jni_headers',
           ],
         }],
+        ['use_x11==1 or use_ozone==1', {
+          'dependencies': [
+            '../ui/platform_window/platform_window.gyp:platform_window',
+          ],
+        }, {
+          'sources!': [
+            'services/native_viewport/platform_viewport.cc',
+          ],
+        }],
         ['use_x11==1', {
           'dependencies': [
             '../ui/platform_window/x11/x11_window.gyp:x11_window',