Revert of ozone: Remove the "drm" software composited platform

ui/ozone/platform/drm/BUILD.gn

Index: ui/ozone/platform/drm/BUILD.gn
diff --git a/ui/ozone/platform/drm/BUILD.gn b/ui/ozone/platform/drm/BUILD.gn
index 1ce6982827df78bea6033cd57a763a5fab7eaa4a..b92283ad74d717bfbf4b4a740263373f3c529632 100644
--- a/ui/ozone/platform/drm/BUILD.gn
+++ b/ui/ozone/platform/drm/BUILD.gn
@@ -18,10 +18,10 @@
   packages = [ "libdrm" ]
 }
 
-source_set("gbm") {
+source_set("drm_common") {
   sources = [
-    "common/client_native_pixmap_factory_gbm.cc",
-    "common/client_native_pixmap_factory_gbm.h",
+    "common/client_native_pixmap_factory_drm.cc",
+    "common/client_native_pixmap_factory_drm.h",
     "common/drm_util.cc",
     "common/drm_util.h",
     "common/scoped_drm_types.cc",
@@ -45,22 +45,14 @@
     "gpu/drm_gpu_display_manager.h",
     "gpu/drm_gpu_platform_support.cc",
     "gpu/drm_gpu_platform_support.h",
+    "gpu/drm_surface.cc",
+    "gpu/drm_surface.h",
+    "gpu/drm_surface_factory.cc",
+    "gpu/drm_surface_factory.h",
     "gpu/drm_vsync_provider.cc",
     "gpu/drm_vsync_provider.h",
     "gpu/drm_window.cc",
     "gpu/drm_window.h",
-    "gpu/gbm_buffer.cc",
-    "gpu/gbm_buffer.h",
-    "gpu/gbm_buffer_base.cc",
-    "gpu/gbm_buffer_base.h",
-    "gpu/gbm_device.cc",
-    "gpu/gbm_device.h",
-    "gpu/gbm_surface.cc",
-    "gpu/gbm_surface.h",
-    "gpu/gbm_surface_factory.cc",
-    "gpu/gbm_surface_factory.h",
-    "gpu/gbm_surfaceless.cc",
-    "gpu/gbm_surfaceless.h",
     "gpu/hardware_display_controller.cc",
     "gpu/hardware_display_controller.h",
     "gpu/hardware_display_plane.cc",
@@ -97,16 +89,24 @@
     "host/drm_window_host.h",
     "host/drm_window_host_manager.cc",
     "host/drm_window_host_manager.h",
-    "ozone_platform_gbm.cc",
-    "ozone_platform_gbm.h",
   ]
 
+  defines = [ "OZONE_IMPLEMENTATION" ]
+
+  if (use_drm_atomic) {
+    defines += [ "USE_DRM_ATOMIC" ]
+    sources += [
+      "gpu/hardware_display_plane_atomic.cc",
+      "gpu/hardware_display_plane_atomic.h",
+      "gpu/hardware_display_plane_manager_atomic.cc",
+      "gpu/hardware_display_plane_manager_atomic.h",
+    ]
+  }
+
   deps = [
-    ":drm_common",
     "//base",
+    "//skia",
     "//ipc",
-    "//skia",
-    "//third_party/minigbm",
     "//ui/base",
     "//ui/display/types",
     "//ui/display/util",
@@ -119,53 +119,93 @@
     "//ui/gfx/geometry",
   ]
 
-  configs = [ ":libdrm" ]
-
-  public_configs = [ "//third_party/khronos:khronos_headers" ]
-
-  defines = []
-
-  if (use_drm_atomic) {
-    defines += [ "USE_DRM_ATOMIC" ]
-    sources += [
-      "gpu/hardware_display_plane_atomic.cc",
-      "gpu/hardware_display_plane_atomic.h",
-      "gpu/hardware_display_plane_manager_atomic.cc",
-      "gpu/hardware_display_plane_manager_atomic.h",
-    ]
-  }
-
-  if (use_mesa_platform_null) {
-    defines += [ "USE_MESA_PLATFORM_NULL" ]
-  }
-
-  if (use_vgem_map) {
-    defines += [ "USE_VGEM_MAP" ]
-
-    sources += [
-      "gpu/client_native_pixmap_vgem.cc",
-      "gpu/client_native_pixmap_vgem.h",
-    ]
-  }
-}
-
-source_set("gbm_unittests") {
-  testonly = true
-  sources = [
-    "gpu/drm_window_unittest.cc",
-    "gpu/hardware_display_controller_unittest.cc",
-    "gpu/hardware_display_plane_manager_unittest.cc",
-    "gpu/screen_manager_unittest.cc",
-    "test/mock_drm_device.cc",
-    "test/mock_drm_device.h",
-  ]
-
-  deps = [
-    "//skia",
-    "//testing/gtest",
-    "//ui/gfx",
-    "//ui/ozone",
-  ]
-
   public_configs = [ ":libdrm" ]
 }
+
+if (ozone_platform_drm) {
+  source_set("drm") {
+    sources = [
+      "ozone_platform_drm.cc",
+      "ozone_platform_drm.h",
+    ]
+
+    deps = [
+      ":drm_common",
+      "//base",
+      "//skia",
+      "//ui/events/ozone:events_ozone_evdev",
+      "//ui/events/ozone:events_ozone_layout",
+    ]
+  }
+
+  source_set("drm_unittests") {
+    testonly = true
+    sources = [
+      "gpu/drm_surface_unittest.cc",
+      "gpu/drm_window_unittest.cc",
+      "gpu/hardware_display_controller_unittest.cc",
+      "gpu/hardware_display_plane_manager_unittest.cc",
+      "gpu/screen_manager_unittest.cc",
+      "test/mock_drm_device.cc",
+      "test/mock_drm_device.h",
+    ]
+
+    deps = [
+      "//skia",
+      "//testing/gtest",
+      "//ui/gfx",
+      "//ui/ozone",
+    ]
+
+    public_configs = [ ":libdrm" ]
+  }
+}
+
+if (ozone_platform_gbm) {
+  source_set("gbm") {
+    sources = [
+      "common/client_native_pixmap_factory_gbm.cc",
+      "common/client_native_pixmap_factory_gbm.h",
+      "gpu/gbm_buffer.cc",
+      "gpu/gbm_buffer.h",
+      "gpu/gbm_buffer_base.cc",
+      "gpu/gbm_buffer_base.h",
+      "gpu/gbm_device.cc",
+      "gpu/gbm_device.h",
+      "gpu/gbm_surface.cc",
+      "gpu/gbm_surface.h",
+      "gpu/gbm_surface_factory.cc",
+      "gpu/gbm_surface_factory.h",
+      "gpu/gbm_surfaceless.cc",
+      "gpu/gbm_surfaceless.h",
+      "ozone_platform_gbm.cc",
+      "ozone_platform_gbm.h",
+    ]
+
+    deps = [
+      ":drm_common",
+      "//base",
+      "//skia",
+      "//third_party/minigbm",
+      "//ui/events/ozone:events_ozone_evdev",
+      "//ui/events/ozone:events_ozone_layout",
+    ]
+
+    public_configs = [ "//third_party/khronos:khronos_headers" ]
+
+    defines = []
+
+    if (use_mesa_platform_null) {
+      defines += [ "USE_MESA_PLATFORM_NULL" ]
+    }
+
+    if (use_vgem_map) {
+      defines += [ "USE_VGEM_MAP" ]
+
+      sources += [
+        "gpu/client_native_pixmap_vgem.cc",
+        "gpu/client_native_pixmap_vgem.h",
+      ]
+    }
+  }
+}