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

ui/ozone/platform/drm/gbm_surface_factory.cc

Index: ui/ozone/platform/drm/gbm_surface_factory.cc
diff --git a/ui/ozone/platform/drm/gbm_surface_factory.cc b/ui/ozone/platform/drm/gbm_surface_factory.cc
index afe8d2cb6644f929ee2bda09965fbf291c5e95f6..189593c747457b343faf6e15f9a722e2976bc44d 100644
--- a/ui/ozone/platform/drm/gbm_surface_factory.cc
+++ b/ui/ozone/platform/drm/gbm_surface_factory.cc
@@ -150,15 +150,14 @@ scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmap(
     gfx::AcceleratedWidget widget,
     gfx::Size size,
     BufferFormat format,
-    BufferUsage usage) {
-  if (usage == MAP)
-    return nullptr;
-
+    BufferUsage usage,
+    gfx::GpuMemoryBufferHandle* handle) {
+  DCHECK(handle || usage == SCANOUT);
   scoped_refptr<GbmDevice> gbm = GetGbmDevice(widget);
   DCHECK(gbm);
 
   scoped_refptr<GbmBuffer> buffer =
-      GbmBuffer::CreateBuffer(gbm, format, size, true);
+      GbmBuffer::CreateBuffer(gbm, format, size, usage == SCANOUT);
   if (!buffer.get())
     return nullptr;
 
@@ -166,6 +165,11 @@ scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmap(
   if (!pixmap->Initialize())
     return nullptr;
 
+  if (usage == MAP) {
+    DCHECK(handle);
+    pixmap->ExportDmaBuf(drm_device_manager_->GetVgemDevice(), handle);
+  }
+
   return pixmap;
 }
 
@@ -202,7 +206,6 @@ bool GbmSurfaceFactory::CanShowPrimaryPlaneAsOverlay() {
 bool GbmSurfaceFactory::CanCreateNativePixmap(BufferUsage usage) {
   switch (usage) {
     case MAP:
-      return false;
     case SCANOUT:
       return true;
   }