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

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

Index: ppapi/native_client/src/trusted/plugin/plugin.gypi
diff --git a/ppapi/native_client/src/trusted/plugin/plugin.gypi b/ppapi/native_client/src/trusted/plugin/plugin.gypi
index e52b8bb18e52783fbbc19fd588889c4d6766a6f9..093cebf1a77bf68fda1de79117e78005da74cd9c 100644
--- a/ppapi/native_client/src/trusted/plugin/plugin.gypi
+++ b/ppapi/native_client/src/trusted/plugin/plugin.gypi
@@ -1,9 +1,10 @@
-# 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',
@@ -52,6 +53,9 @@
         'cflags': [
           '-Wno-long-long',
         ],
+        'cflags!': [
+          '-Wno-unused-parameter', # be a bit stricter to match NaCl flags.
+        ],
         'conditions': [
           ['asan!=1', {
             'ldflags': [
@@ -77,6 +81,9 @@
         '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',