Add custom interstitial for captive portals.

chrome/browser/captive_portal/captive_portal_service.cc

Index: chrome/browser/captive_portal/captive_portal_service.cc
diff --git a/chrome/browser/captive_portal/captive_portal_service.cc b/chrome/browser/captive_portal/captive_portal_service.cc
index 93c37a8c1b81f69c8f9c174e934e7a1276f8a3bd..fa83508caad112cb6a22ade1cc9a915fc7dbd67e 100644
--- a/chrome/browser/captive_portal/captive_portal_service.cc
+++ b/chrome/browser/captive_portal/captive_portal_service.cc
@@ -194,7 +194,8 @@ CaptivePortalService::CaptivePortalService(Profile* profile)
       enabled_(false),
       last_detection_result_(captive_portal::RESULT_INTERNET_CONNECTED),
       num_checks_with_same_result_(0),
-      test_url_(captive_portal::CaptivePortalDetector::kDefaultURL) {
+      test_url_(captive_portal::CaptivePortalDetector::kDefaultURL),
+      portal_detection_enabled_(true) {
   // The order matters here:
   // |resolve_errors_with_web_service_| must be initialized and |backoff_entry_|
   // created before the call to UpdateEnabledState.
@@ -211,9 +212,17 @@ CaptivePortalService::CaptivePortalService(Profile* profile)
 CaptivePortalService::~CaptivePortalService() {
 }
 
+void CaptivePortalService::SetPortalDetectionEnabledForTest(bool enabled) {
+  portal_detection_enabled_ = enabled;
+}
+
 void CaptivePortalService::DetectCaptivePortal() {
   DCHECK(CalledOnValidThread());
 
+  // Detection should be disabled only in tests.
+  if (!portal_detection_enabled_)
+    return;
+
   // If a request is pending or running, do nothing.
   if (state_ == STATE_CHECKING_FOR_PORTAL || state_ == STATE_TIMER_RUNNING)
     return;