gfx: Use unsigned strides for gpu memory buffers.

ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc

Index: ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc
diff --git a/ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc b/ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc
index 335f80b0f4e6ef59ed304202f3f06e1d3d06e2fe..3d7fd357c2051798797671b90434a524f74603c2 100644
--- a/ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc
+++ b/ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc
@@ -26,7 +26,7 @@ class ClientNativePixmapGbm : public ClientNativePixmap {
     return nullptr;
   }
   void Unmap() override { NOTREACHED(); }
-  void GetStride(int* stride) const override { NOTREACHED(); }
+  void GetStride(uint32_t* stride) const override { NOTREACHED(); }
 };
 
 }  // namespace