Android: Add no-op configs for hiding symbols by default

build/config/android/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/android/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 assert(is_android)
 
 # This is included by reference in the //build/config/compiler config that
@@ skipping 182 matching lines @@
   cflags = [ "-fPIE" ]
   asmflags = [ "-fPIE" ]
   ldflags = [ "-pie" ]
 }
 
 config("hide_native_jni_exports") {
   ldflags = [ "-Wl,--version-script=" +
               rebase_path("//build/android/android_no_jni_exports.lst") ]
 }
 
+config("hide_all_but_jni_onload") {
+  # TODO(agrieve): https://codereview.chromium.org/2633593004/
+}
+
+config("hide_all_but_jni") {
+  # TODO(agrieve): https://codereview.chromium.org/2633593004/
+}
+
 # Instrumentation -------------------------------------------------------------
 #
 # The BUILDCONFIG file sets the "default_cygprofile_instrumentation" config on
 # targets by default. You can override whether the cygprofile instrumentation is
 # used on a per-target basis:
 #
 # configs -= [ "//build/config/android:default_cygprofile_instrumentation" ]
 # configs += [ "//build/config/android:no_cygprofile_instrumentation" ]
 
 config("default_cygprofile_instrumentation") {
@@ skipping 15 matching lines @@
 
       # Avoid errors with current NDK:
       # "third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/include/arm_neon.h:3426:3: error: argument must be a constant"
       "-finstrument-functions-exclude-file-list=arm_neon.h",
     ]
   }
 }
 
 config("no_cygprofile_instrumentation") {
 }