Always set symbol visibility when compiling with GCC / Clang.

third_party/harfbuzz-ng/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 
 declare_args() {
   # Blink uses a cutting-edge version of Harfbuzz; most Linux distros do not
@@ skipping 172 matching lines @@
     }
 
     # When without -fvisibility=hidden for pango to use the harfbuzz
     # in the tree, all symbols pango needs must be included, or
     # pango uses mixed versions of harfbuzz and leads to crash.
     # See crbug.com/462689.
     if (is_linux && use_pango && !is_chromeos && !is_official_build &&
         current_cpu != "arm" && current_cpu != "mipsel") {
       deps += [ "//build/linux:freetype2" ]
       configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+      configs += [ "//build/config/gcc:symbol_visibility_default" ]
       configs += [ "//build/config/linux:glib" ]
       sources += [
         "src/hb-ft.cc",
         "src/hb-ft.h",
         "src/hb-glib.cc",
         "src/hb-glib.h",
       ]
     }
   }
 }