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

ios/web_view/BUILD.gn

Index: ios/web_view/BUILD.gn
diff --git a/ios/web_view/BUILD.gn b/ios/web_view/BUILD.gn
index 4f0d6493f509064a6b787207304934656f3509b8..bcfc011ff7fdb172343f1c1be4b8777d0f831fcf 100644
--- a/ios/web_view/BUILD.gn
+++ b/ios/web_view/BUILD.gn
@@ -39,6 +39,10 @@ ios_web_view_public_headers = [
 ]
 
 ios_web_view_sources = [
+  "internal/app/application_context.cc",
+  "internal/app/application_context.h",
+  "internal/app/web_view_io_thread.h",
+  "internal/app/web_view_io_thread.mm",
   "internal/cwv_html_element.mm",
   "internal/cwv_html_element_internal.h",
   "internal/cwv_navigation_action.mm",
@@ -90,15 +94,20 @@ ios_web_view_deps = [
   ":generate_license",
   ":packed_resources",
   "//base",
+  "//components/flags_ui",
   "//components/infobars/core",
   "//components/keyed_service/core",
   "//components/keyed_service/ios",
+  "//components/net_log",
   "//components/pref_registry",
   "//components/prefs",
+  "//components/proxy_config",
+  "//components/ssl_config",
   "//components/translate/core/browser",
   "//components/translate/core/common",
   "//components/translate/ios/browser",
   "//google_apis",
+  "//ios/components/io_thread",
   "//ios/net",
   "//ios/web",
   "//ios/web:reload_type",