Initialize ios/web_view translate with a system-wide URLRequestContext.

ios/web_view/internal/web_view_web_client.mm

Index: ios/web_view/internal/web_view_web_client.mm
diff --git a/ios/web_view/internal/web_view_web_client.mm b/ios/web_view/internal/web_view_web_client.mm
index 319b5e32e24516c62bcb8a0e38e1b5f5d388891c..41db435fe644687d199d25db35bb9fbe79f99dc7 100644
--- a/ios/web_view/internal/web_view_web_client.mm
+++ b/ios/web_view/internal/web_view_web_client.mm
@@ -4,6 +4,7 @@
 
 #import "ios/web_view/internal/web_view_web_client.h"
 
+#include "base/command_line.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ios/web/public/user_agent.h"
 #include "ios/web_view/internal/web_view_browser_state.h"
@@ -22,7 +23,8 @@ WebViewWebClient::WebViewWebClient() : web_main_parts_(nullptr) {}
 WebViewWebClient::~WebViewWebClient() = default;
 
 web::WebMainParts* WebViewWebClient::CreateWebMainParts() {
-  web_main_parts_ = new WebViewWebMainParts();
+  web_main_parts_ =
+      new WebViewWebMainParts(*base::CommandLine::ForCurrentProcess());
   return web_main_parts_;
 }