Build nacl plugin with normal chromium warning levels (higher levels),

ppapi/native_client/src/trusted/plugin/plugin.gypi

-# Copyright (c) 2011 The Native Client Authors. All rights reserved.
+# Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
+    'chromium_code': 1,  # Use higher warning level.
     'common_sources': [
       'file_downloader.cc',
       'json_manifest.cc',
       'module_ppapi.cc',
       'nacl_subprocess.cc',
       'nexe_arch.cc',
       'plugin.cc',
       'pnacl_coordinator.cc',
       'pnacl_resources.cc',
       'scriptable_plugin.cc',
@@ skipping 28 matching lines @@
     },
     'conditions': [
       ['OS=="linux"', {
         'defines': [
           'XP_UNIX',
           'MOZ_X11',
         ],
         'cflags': [
           '-Wno-long-long',
         ],
+        'cflags!': [
+          '-Wno-unused-parameter', # be a bit stricter to match NaCl flags.
+        ],
         'conditions': [
           ['asan!=1', {
             'ldflags': [
               # Catch unresolved symbols.
               '-Wl,-z,defs',
             ],
           }],
         ],
         'libraries': [
           '-ldl',
           '-lX11',
           '-lXt',
         ],
       }],
       ['OS=="mac"', {
         'defines': [
           'XP_MACOSX',
           'XP_UNIX',
           'TARGET_API_MAC_CARBON=1',
           'NO_X11',
           'USE_SYSTEM_CONSOLE',
         ],
         'cflags': [
           '-Wno-long-long',
         ],
+        'cflags!': [
+          '-Wno-unused-parameter', # be a bit stricter to match NaCl flags.
+        ],
         'link_settings': {
           'libraries': [
             '$(SDKROOT)/System/Library/Frameworks/Carbon.framework',
           ],
         },
       }],
       ['OS=="win"', {
         'defines': [
           'XP_WIN',
           'WIN32',
           '_WINDOWS'
         ],
         'flags': [
           '-fPIC',
           '-Wno-long-long',
         ],
         'link_settings': {
           'libraries': [
             '-lgdi32.lib',
             '-luser32.lib',
           ],
         },
       }],
     ],
   },
 }