[Ozone-Gbm] Allow changing the MESA platform

BUG=427959
NOTRY=true

Review URL: https://codereview.chromium.org/810293002

Cr-Commit-Position: refs/heads/master@{#312525}

4 files changed, 22 insertions, 0 deletions

diff --git a/ui/ozone/platform/dri/BUILD.gn b/ui/ozone/platform/dri/BUILD.gn
index 1e25550..b8cd4a2 100644
--- a/ui/ozone/platform/dri/BUILD.gn
+++ b/ui/ozone/platform/dri/BUILD.gn
@@ -5,6 +5,10 @@
 import("//build/config/linux/pkg_config.gni")
 import("//ui/ozone/ozone.gni")
 
+declare_args() {
+  use_mesa_platform_null = false
+}
+
 pkg_config("libdrm") {
   packages = [ "libdrm" ]
 }
@@ -153,5 +157,9 @@ if (ozone_platform_gbm) {
     ]
 
     public_configs = [ ":libgbm" ]
+
+    if (use_mesa_platform_null) {
+      defines += [ "USE_MESA_PLATFORM_NULL" ]
+    }
   }
 }
diff --git a/ui/ozone/platform/dri/gbm.gypi b/ui/ozone/platform/dri/gbm.gypi
index dd60ba4..bdf9833 100644
--- a/ui/ozone/platform/dri/gbm.gypi
+++ b/ui/ozone/platform/dri/gbm.gypi
@@ -10,6 +10,7 @@
     'internal_ozone_platforms': [
       'gbm',
     ],
+    'use_mesa_platform_null%': 0,
   },
   'targets': [
     {
@@ -45,6 +46,11 @@
         'ozone_platform_gbm.cc',
         'ozone_platform_gbm.h',
       ],
+      'conditions': [
+        ['use_mesa_platform_null==1', {
+          'defines': ['USE_MESA_PLATFORM_NULL'],
+        }],
+      ],
     },
   ],
 }
diff --git a/ui/ozone/platform/dri/gbm_surface_factory.cc b/ui/ozone/platform/dri/gbm_surface_factory.cc
index cb0127b..cda036a 100644
--- a/ui/ozone/platform/dri/gbm_surface_factory.cc
+++ b/ui/ozone/platform/dri/gbm_surface_factory.cc
@@ -87,7 +87,11 @@ void GbmSurfaceFactory::InitializeGpu(
 }
 
 intptr_t GbmSurfaceFactory::GetNativeDisplay() {
+#if defined(USE_MESA_PLATFORM_NULL)
+  return EGL_DEFAULT_DISPLAY;
+#else
   return reinterpret_cast<intptr_t>(device_);
+#endif
 }
 
 int GbmSurfaceFactory::GetDrmFd() {
diff --git a/ui/ozone/platform/dri/ozone_platform_gbm.cc b/ui/ozone/platform/dri/ozone_platform_gbm.cc
index f06588b..e76493e 100644
--- a/ui/ozone/platform/dri/ozone_platform_gbm.cc
+++ b/ui/ozone/platform/dri/ozone_platform_gbm.cc
@@ -200,6 +200,10 @@ class OzonePlatformGbm : public OzonePlatform {
 
 OzonePlatform* CreateOzonePlatformGbm() {
   base::CommandLine* cmd = base::CommandLine::ForCurrentProcess();
+#if defined(USE_MESA_PLATFORM_NULL)
+  // Only works with surfaceless.
+  cmd->AppendSwitch(switches::kOzoneUseSurfaceless);
+#endif
   return new OzonePlatformGbm(cmd->HasSwitch(switches::kOzoneUseSurfaceless));
 }