Used space visible in SD Card bar graph

Bug 4544470

Change-Id: Iccae9bb568f1f7baf81c702f29f7a9e238d39d2b

src/com/android/settings/deviceinfo/StorageMeasurement.java

@@ -478,6 +478,7 @@ public class StorageMeasurement {
         File top = new File(mStorageVolume.getPath());
         mFileInfoForMisc = new ArrayList<FileInfo>();
         File[] files = top.listFiles();
+        if (files == null) return;
         final int len = files.length;
         // Get sizes of all top level nodes except the ones already computed...
         long counter = 0;
@@ -524,4 +525,11 @@ public class StorageMeasurement {
             return mFileName  + " : " + mSize + ", id:" + mId;
         }
     }
+
+    /**
+     * TODO remove this method, only used because external SD Card needs a special treatment.
+     */
+    boolean isPrimary() {
+        return mIsPrimary;
+    }
 }