AAPT2: Record source/comments for compound values' children

Values like styles or arrays have children which need to have
their source and comments preserved.

Change-Id: I6fc713ba36627e6d66c7930b4080cc1403bac207
diff --git a/tools/aapt2/unflatten/BinaryResourceParser.h b/tools/aapt2/unflatten/BinaryResourceParser.h
index 73fcf52..0745a59 100644
--- a/tools/aapt2/unflatten/BinaryResourceParser.h
+++ b/tools/aapt2/unflatten/BinaryResourceParser.h
@@ -91,6 +91,13 @@
                                               const ConfigDescription& config,
                                               const android::ResTable_map_entry* map);
 
+    /**
+     * If the mapEntry is a special type that denotes meta data (source, comment), then it is
+     * read and added to the Value.
+     * Returns true if the mapEntry was meta data.
+     */
+    bool collectMetaData(const android::ResTable_map& mapEntry, Value* value);
+
     IAaptContext* mContext;
     ResourceTable* mTable;