[gn] Have the dump_breakpad_symbols produced an archive of breakpad symbols

IN-851 #comment

Change-Id: I123dcc5bdd7bfe712d032ec9ddfc64b794812ba3
diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index be027c5..4fd03b2 100644
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -152,6 +152,7 @@
   # find and upload the symbol files.
   outputs = [
     "$root_out_dir/breakpad_symbols/symbol_file_mappings.json",
+    "$root_out_dir/breakpad_symbols/breakpad_symbols.tar.gz",
   ]
 
   depfile = "${outputs[0]}.d"
@@ -165,6 +166,8 @@
            rebase_path(outputs[0], root_build_dir),
            "-depfile",
            rebase_path(depfile, root_build_dir),
+           "-tar-file",
+           rebase_path(outputs[1], root_build_dir),
          ] + rebase_path(sources, root_build_dir)
 }