Fix Flutter's Linux build

runtime/bin/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 
 declare_args() {
   dart_io_support = false
 
   # TODO(zra, jamesr): Remove this check once we start building boringssl for
   # the fuchsia port.
@@ skipping 342 matching lines @@
     "io_natives.cc",
     "io_natives.h",
     "embedded_dart_io.cc",
     "embedded_dart_io.h",
     "log_android.cc",
     "log_linux.cc",
     "log_macos.cc",
     "log_win.cc",
     "log.h",
   ]
+  if (is_linux) {
+    sources += [ "../../third_party/root_certificates/root_certificates.cc"]
+  }
 
   include_dirs = [
     "..",
     "//third_party"
   ]
 }
 }  # !is_fuchsia
 
 
 action("generate_snapshot_bin") {
@@ skipping 84 matching lines @@
       "..",
       "../include"
     ]
 
     deps = [
       ":dart_snapshot_cc",
       ":libdart_embedder_noio",
     ]
   }
 }