Add type for testing to interstitials.

chrome/browser/ui/login/login_interstitial_delegate.cc

Index: chrome/browser/ui/login/login_interstitial_delegate.cc
diff --git a/chrome/browser/ui/login/login_interstitial_delegate.cc b/chrome/browser/ui/login/login_interstitial_delegate.cc
index b4b8dfb73603b29875f008970ff1a631bd76a40a..bd487559a52b9b1eb6cdf8806476d17f18222f85 100644
--- a/chrome/browser/ui/login/login_interstitial_delegate.cc
+++ b/chrome/browser/ui/login/login_interstitial_delegate.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/ui/login/login_interstitial_delegate.h"
 
+content::InterstitialPageDelegate::TypeID
+    LoginInterstitialDelegate::kTypeForTesting =
+        &LoginInterstitialDelegate::kTypeForTesting;
+
 LoginInterstitialDelegate::LoginInterstitialDelegate(
     content::WebContents* web_contents,
     const GURL& request_url,
@@ -25,6 +29,11 @@ void LoginInterstitialDelegate::CommandReceived(const std::string& command) {
   callback_.Run();
 }
 
+content::InterstitialPageDelegate::TypeID
+LoginInterstitialDelegate::GetTypeForTesting() const {
+  return LoginInterstitialDelegate::kTypeForTesting;
+}
+
 std::string LoginInterstitialDelegate::GetHTMLContents() {
   // Showing an interstitial results in a new navigation, and a new navigation
   // closes all modal dialogs on the page. Therefore the login prompt must be