ozone: Implement PlatformObject<T> for platform-specific objects

ui/ozone/ozone.gyp

Index: ui/ozone/ozone.gyp
diff --git a/ui/ozone/ozone.gyp b/ui/ozone/ozone.gyp
index 3813b8d5c0cba6b15aadd1c332b5faf339f65e3f..0d17d4f14354018d77d17cd1fe7d65eac4d2f172 100644
--- a/ui/ozone/ozone.gyp
+++ b/ui/ozone/ozone.gyp
@@ -30,14 +30,23 @@
         'OZONE_IMPLEMENTATION',
       ],
       'variables': {
-        'platform_list_file': '<(SHARED_INTERMEDIATE_DIR)/ui/ozone/ozone_platform_list.cc',
+        'platform_list_cc_file': '<(INTERMEDIATE_DIR)/ui/ozone/platform_list.cc',
+        'platform_list_h_file': '<(SHARED_INTERMEDIATE_DIR)/ui/ozone/platform_list.h',
+        'platform_list_txt_file': '<(SHARED_INTERMEDIATE_DIR)/ui/ozone/platform_list.txt',
+        'constructor_list_cc_file': '<(INTERMEDIATE_DIR)/ui/ozone/constructor_list.cc',
         'ozone_platforms': [
           '<@(external_ozone_platforms)',
           '<@(internal_ozone_platforms)',
         ],
       },
+      'include_dirs': [
+        '<(SHARED_INTERMEDIATE_DIR)',
+      ],
       'sources': [
-        '<(platform_list_file)',
+        '<(platform_list_cc_file)',
+        '<(platform_list_h_file)',
+        '<(constructor_list_cc_file)',
+
         # common/chromeos files are excluded automatically when building with
         # chromeos=0, by exclusion rules in filename_rules.gypi due to the
         # 'chromeos' folder name.
@@ -47,6 +56,8 @@
         'ozone_platform.h',
         'ozone_switches.cc',
         'ozone_switches.h',
+        'platform_selection.cc',
+        'platform_selection.h',
         '<@(external_ozone_platform_files)',
       ],
       'actions': [
@@ -59,16 +70,42 @@
             '<(generator_path)',
           ],
           'outputs': [
-            '<(platform_list_file)',
+            '<(platform_list_cc_file)',
+            '<(platform_list_h_file)',
+            '<(platform_list_txt_file)',
           ],
           'action': [
             'python',
             '<(generator_path)',
-            '--output_file=<(platform_list_file)',
+            '--output_cc=<(platform_list_cc_file)',
+            '--output_h=<(platform_list_h_file)',
+            '--output_txt=<(platform_list_txt_file)',
             '--default=<(ozone_platform)',
             '<@(ozone_platforms)',
           ],
         },
+        {
+          'action_name': 'generate_constructor_list',
+          'variables': {
+            'generator_path': 'generate_constructor_list.py',
+          },
+          'inputs': [
+            '<(generator_path)',
+            '<(platform_list_txt_file)',
+          ],
+          'outputs': [
+            '<(constructor_list_cc_file)',
+          ],
+          'action': [
+            'python',
+            '<(generator_path)',
+            '--platform_list=<(platform_list_txt_file)',
+            '--output_cc=<(constructor_list_cc_file)',
+            '--namespace=ui',
+            '--typename=OzonePlatform',
+            '--include="ui/ozone/ozone_platform.h"'
+          ],
+        },
       ],
       'conditions': [
         ['use_udev == 0', {