DRW: Make shaded batch validation more correct

This is in order to support garbage collection of unused Custom data layer uploaded to the GPU.

Actual Garbage Collection is not added by this commit.

source/blender/makesrna/intern/rna_space.c

@@ -914,17 +914,6 @@ static void rna_3DViewShading_type_update(Main *bmain, Scene *scene, PointerRNA
     return;
   }
 
-  for (Material *ma = bmain->materials.first; ma; ma = ma->id.next) {
-    /* XXX Dependency graph does not support CD mask tracking,
-     * so we trigger  materials shading for until it's properly supported.
-     * This is to ensure material batches are all recreated when switching
-     * shading type. In the future DEG should replace this and just tag
-     * the meshes itself.
-     * This hack just tag BKE_MESH_BATCH_DIRTY_SHADING for every mesh that
-     * have a material. (see T55059) */
-    DEG_id_tag_update(&ma->id, ID_RECALC_SHADING);
-  }
-
   View3DShading *shading = ptr->data;
   if (shading->type == OB_MATERIAL ||
       (shading->type == OB_RENDER &&