Split HttpNetworkSession::Params into two structs.

ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm

Index: ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm
diff --git a/ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm b/ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm
index 0d0dfbfad07d9841fc96f628ca5144693bb4751e..feea79b7f6cf53685686fc8b9675583f21182cc9 100644
--- a/ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm
+++ b/ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm
@@ -305,11 +305,12 @@ ChromeBrowserStateImplIOData::InitializeAppRequestContext(
       new net::ChannelIDService(new net::DefaultChannelIDStore(nullptr)));
 
   // Build a new HttpNetworkSession that uses the new ChannelIDService.
-  net::HttpNetworkSession::Params network_params =
-      http_network_session_->params();
-  network_params.channel_id_service = channel_id_service.get();
+  net::HttpNetworkSession::Context session_context =
+      http_network_session_->context();
+  session_context.channel_id_service = channel_id_service.get();
   std::unique_ptr<net::HttpNetworkSession> http_network_session(
-      new net::HttpNetworkSession(network_params));
+      new net::HttpNetworkSession(http_network_session_->params(),
+                                  session_context));
 
   // Use a separate HTTP disk cache for isolated apps.
   std::unique_ptr<net::HttpCache::BackendFactory> app_backend =