Revert "Chromecast buildfix: update SelectClientCertificate API."

This reverts commit d9bd422472cfa491761ca6d644345f79cd0eb9ad.

See: https://codereview.chromium.org/780383002

R=lcwu@chromium.org
BUG=None

Review URL: https://codereview.chromium.org/782293005

Cr-Commit-Position: refs/heads/master@{#307386}
diff --git a/chromecast/browser/cast_content_browser_client.cc b/chromecast/browser/cast_content_browser_client.cc
index cf572382..ce8af67 100644
--- a/chromecast/browser/cast_content_browser_client.cc
+++ b/chromecast/browser/cast_content_browser_client.cc
@@ -152,7 +152,6 @@
 void CastContentBrowserClient::SelectClientCertificate(
     int render_process_id,
     int render_view_id,
-    const net::HttpNetworkSession* network_session,
     net::SSLCertRequestInfo* cert_request_info,
     const base::Callback<void(net::X509Certificate*)>& callback) {
   GURL requesting_url("https://" + cert_request_info->host_and_port.ToString());
diff --git a/chromecast/browser/cast_content_browser_client.h b/chromecast/browser/cast_content_browser_client.h
index c28c514..8b47b3c 100644
--- a/chromecast/browser/cast_content_browser_client.h
+++ b/chromecast/browser/cast_content_browser_client.h
@@ -53,7 +53,6 @@
   virtual void SelectClientCertificate(
       int render_process_id,
       int render_frame_id,
-      const net::HttpNetworkSession* network_session,
       net::SSLCertRequestInfo* cert_request_info,
       const base::Callback<void(net::X509Certificate*)>& callback) override;
   virtual bool CanCreateWindow(