Land http://codereview.chromium.org/159067:

chrome/browser/tab_contents/interstitial_page.cc

Index: chrome/browser/tab_contents/interstitial_page.cc
diff --git a/chrome/browser/tab_contents/interstitial_page.cc b/chrome/browser/tab_contents/interstitial_page.cc
index 5cc028831d437a54c2bf264720431ce2e9681dac..b7e739e8351473231e1c5bd32aa20a109d3a8ae8 100644
--- a/chrome/browser/tab_contents/interstitial_page.cc
+++ b/chrome/browser/tab_contents/interstitial_page.cc
@@ -591,3 +591,7 @@ void InterstitialPage::InterstitialPageRVHViewDelegate::OnFindReply(
     int request_id, int number_of_matches, const gfx::Rect& selection_rect,
     int active_match_ordinal, bool final_update) {
 }
+
+int InterstitialPage::GetBrowserWindowID() const {
+  return tab_->GetBrowserWindowID();
+}