This is UI side unreadable device support.

chrome/common/extensions/api/extension_api.json

Index: chrome/common/extensions/api/extension_api.json
diff --git a/chrome/common/extensions/api/extension_api.json b/chrome/common/extensions/api/extension_api.json
index 7c6ca95e22abaea1fdb47e0d1dc3560a1cdbe9b8..31cabb73de4a9e69e5eed3c704fdc3bc09554f4c 100644
--- a/chrome/common/extensions/api/extension_api.json
+++ b/chrome/common/extensions/api/extension_api.json
@@ -6612,6 +6612,10 @@
             "type": "string",
             "enum": ["device", "file", "network"],
             "description": "Type of the mount."
+          },
+          "mountCondition": {
+            "type": "string",
+            "description": "Additional data about mount, for example, that the filesystem is not supported."
           }
         }
       },
@@ -7016,6 +7020,17 @@
             "description": "Device's mount path."
           }
         ]
+      },
+      {
+        "name": "formatUnmountedDevice",
+        "description": "Formats a unmounted device",
+        "parameters": [
+          {
+            "name": "filePath",
+            "type": "string",
+            "description": "Device's file path."
+          }
+        ]
       }
     ],
     "events": [