PAC 支持被禁用，因为没有系统实现

【问题标题】：PAC support disabled because there is no system implementationPAC 支持被禁用，因为没有系统实现
【发布时间】：2013-12-31 16:51:59
【问题描述】：

我最近将我的 Nexus 4 升级到了 Android 4.4。在调试我的应用程序时，我发现了消息W/chromium(14962): [WARNING:proxy_service.cc(888)] PAC support disabled because there is no system implementation

什么意思？

Logcat

12-12 17:38:56.726: V/WebViewChromium(14962): Binding Chromium to the main looper Looper{41f91588}
12-12 17:38:56.736: I/chromium(14962): [INFO:library_loader_hooks.cc(112)] Chromium logging enabled: level = 0, default verbosity = 0
12-12 17:38:56.736: I/BrowserProcessMain(14962): Initializing chromium process, renderers=0
12-12 17:38:56.746: W/chromium(14962): [WARNING:proxy_service.cc(888)] PAC support disabled because there is no system implementation

【问题讨论】：

标签： android chromium

【解决方案1】：

我认为你可以放心地忽略这个。它在 Chromium 浏览器引擎中有点硬编码。

如果您查看 Chromium 来源 (https://chromium.googlesource.com/chromium/src.git/+/master/net/proxy/proxy_service.cc) 并查看 ProxyService::CreateUsingSystemProxyResolver，您会发现

if (!ProxyResolverFactoryForSystem::IsSupported()) {
  LOG(WARNING) << "PAC support disabled because there is no "
                "system implementation";
  return CreateWithoutProxyResolver(proxy_config_service, net_log);
}

如果您不在 Windows 或 MacOS 上，ProxyResolverFactoryForSystem::IsSupported() 只是返回 false

class ProxyResolverFactoryForSystem : public ProxyResolverFactory {
  //[...]
  static bool IsSupported() {
#if defined(OS_WIN) || defined(OS_MACOSX)
    return true;
#else
    return false;
#endif
  }
};

【讨论】：