ProxyServer commandline flag for android webview

android_webview/browser/net/aw_url_request_context_getter.cc

Index: android_webview/browser/net/aw_url_request_context_getter.cc
diff --git a/android_webview/browser/net/aw_url_request_context_getter.cc b/android_webview/browser/net/aw_url_request_context_getter.cc
index 7ad7c4c7bc648a1eb9927ad99ee878826dfdb0e3..f8791a02b74ebbc89c0e37dd6408911fe86e3ddb 100644
--- a/android_webview/browser/net/aw_url_request_context_getter.cc
+++ b/android_webview/browser/net/aw_url_request_context_getter.cc
@@ -228,8 +228,17 @@ void AwURLRequestContextGetter::InitializeURLRequestContext() {
   // Android provides a local HTTP proxy that handles all the proxying.
   // Create the proxy without a resolver since we rely on this local HTTP proxy.
   // TODO(sgurun) is this behavior guaranteed through SDK?
-  builder.set_proxy_service(net::ProxyService::CreateWithoutProxyResolver(
-      std::move(proxy_config_service_), net_log_.get()));
+
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  if (command_line.HasSwitch(switches::kProxyServer)) {
+    std::string proxy =
+        command_line.GetSwitchValueASCII(switches::kProxyServer);
+    builder.set_proxy_service(net::ProxyService::CreateFixed(proxy));
+  } else {
+    builder.set_proxy_service(net::ProxyService::CreateWithoutProxyResolver(
+        std::move(proxy_config_service_), net_log_.get()));
+  }
   builder.set_net_log(net_log_.get());
   builder.SetCookieAndChannelIdStores(base::MakeUnique<AwCookieStoreWrapper>(),
                                       std::move(channel_id_service));