ozone: Implement zero/one-copy texture for Ozone GBM.

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 801b02146f47ef5f826cd22e5e25df558cb89ea7..ebaf281957e82926a048b3c833dee947086d8bee 100644
--- a/ui/ozone/platform/drm/BUILD.gn
+++ b/ui/ozone/platform/drm/BUILD.gn
@@ -8,6 +8,7 @@ import("//ui/ozone/ozone.gni")
 declare_args() {
   use_mesa_platform_null = false
   use_drm_atomic = false
+  ozone_use_vgem_map = false
 }
 
 pkg_config("libdrm") {
@@ -165,6 +166,8 @@ if (ozone_platform_gbm) {
     sources = [
       "common/client_native_pixmap_factory_gbm.cc",
       "common/client_native_pixmap_factory_gbm.h",
+      "gpu/client_native_pixmap_vgem.cc",
+      "gpu/client_native_pixmap_vgem.h",
       "gpu/gbm_buffer.cc",
       "gpu/gbm_buffer.h",
       "gpu/gbm_buffer_base.cc",
@@ -197,5 +200,9 @@ if (ozone_platform_gbm) {
     if (use_mesa_platform_null) {
       defines += [ "USE_MESA_PLATFORM_NULL" ]
     }
+
+    if (ozone_use_vgem_map) {
+      defines += [ "OZONE_USE_VGEM_MAP" ]
+    }
   }
 }