ozone: Fix the way platform tests link ozone

ui/ozone/ozone.gyp

Index: ui/ozone/ozone.gyp
diff --git a/ui/ozone/ozone.gyp b/ui/ozone/ozone.gyp
index 399a6b5c5a72dd1b261103a67a8cc56afa5bc038..3c9c860b4a97ced1222aedee0941d84af1a75c79 100644
--- a/ui/ozone/ozone.gyp
+++ b/ui/ozone/ozone.gyp
@@ -83,9 +83,9 @@
       ],
     },
     {
-      # GN version: //ui/ozone
-      'target_name': 'ozone',
-      'type': '<(component)',
+      # GN version: //ui/ozone:platform
+      'target_name': 'ozone_platform',
+      'type': 'static_library',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/ipc/ipc.gyp:ipc',
@@ -195,13 +195,23 @@
       ],
     },
     {
+      # GN version: //ui/ozone
+      'target_name': 'ozone',
+      'type': '<(component)',
+      'sources': [
+        'empty.cc',
+      ],
+      'dependencies': [
+        'ozone_platform',
+      ],
+    },
+    {
       'target_name': 'ozone_unittests',
       'type': '<(gtest_target_type)',
       'sources': [
         'run_all_unittests.cc',
       ],
       'dependencies': [
-        'ozone',
         '../../base/base.gyp:base',
         '../../base/base.gyp:test_support_base',
         '../../testing/gtest.gyp:gtest',