Enable about:nacl and correct symbol visibility for the plugin

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 4379 matching lines @@
                   # crtbegin_dynamic.o should be the last item in ldflags.
                   '<(android_ndk_lib)/crtbegin_dynamic.o',
                 ],
                 'libraries': [
                   # crtend_android.o needs to be the last item in libraries.
                   # Do not add any libraries after this!
                   '<(android_ndk_lib)/crtend_android.o',
                 ],
               }],
               ['_type=="shared_library" or _type=="loadable_module"', {
+                'ldflags!': [
+                  '-Wl,--exclude-libs=ALL',
+                ],
                 'ldflags': [
                   '-Wl,-shared,-Bsymbolic',
                 ],
                 'conditions': [
                   ['android_webview_build==0', {
                     'ldflags': [
                       # crtbegin_so.o should be the last item in ldflags.
                       '<(android_ndk_lib)/crtbegin_so.o',
                     ],
                     'libraries': [
@@ skipping 1019 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }