Adding support to retrieve remaining and total space on disk/file shelf.

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 1326a40552d834dd83525b02f525d4f03fdf5d0f..35bad6dd0d866db9de8b289ca825391a258b798b 100644
--- a/chrome/common/extensions/api/extension_api.json
+++ b/chrome/common/extensions/api/extension_api.json
@@ -6635,6 +6635,21 @@
         }
       },
       {
+        "id": "MountPointSizeStats",
+        "type": "object",
+        "description": "Information about total and remaining size on the mount point.",
+        "properties": {
+          "totalSizeKB": {
+            "type": "integer",
+            "description": "Total available size on the mount point."
+          },
+          "remainingSizeKB": {
+            "type": "integer",
+            "description": "Remaining available size on the mount point."
+          }
+        }
+      },
+      {
         "id": "VolumeMetadata",
         "type": "object",
         "description": "Mounted disk volume metadata.",
@@ -7026,6 +7041,29 @@
         ]
       },
       {
+        "name": "getSizeStats",
+        "description": "Retrieves total and remaining size of a mount point.",
+        "parameters": [
+          {
+            "name": "mountPath",
+            "type": "string",
+            "description": "Mount point path."
+          },
+          {
+            "name": "callback",
+            "type": "function",
+            "optional": false,
+            "parameters": [
+              {
+                "name" : "sizeStats",
+                "$ref": "MountPointSizeStats",
+                "description": "Name/value pairs of size stats."
+              }
+            ]
+          }
+        ]
+      },
+      {
         "name": "formatDevice",
         "description": "Formats a mounted device",
         "parameters": [