Fix flashing window when deleting profile

chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc

Index: chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc
diff --git a/chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc b/chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc
index 1fceceb53eea3634f442feb09c13a82772852741..eb983dc26d78fff1761fada8ddc78dfdebe74c38 100644
--- a/chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc
+++ b/chrome/browser/ui/webui/sync_promo/sync_promo_handler.cc
@@ -200,11 +200,18 @@ void SyncPromoHandler::HandleCloseSyncPromo(const base::ListValue* args) {
   if (!username.empty())
     prefs_->SetBoolean(prefs::kSyncPromoShowNTPBubble, true);
 
-  GURL url = SyncPromoUI::GetNextPageURLForSyncPromoURL(
-      web_ui()->GetWebContents()->GetURL());
-  OpenURLParams params(
-      url, Referrer(), CURRENT_TAB, content::PAGE_TRANSITION_LINK, false);
-  web_ui()->GetWebContents()->OpenURL(params);
+  // If the browser window is being closed then don't try to navigate to
+  // another URL. This prevents the browser window from flashing during
+  // close.
+  Browser* browser =
+      BrowserList::FindBrowserWithWebContents(web_ui()->GetWebContents());
+  if (browser && !browser->IsAttemptingToCloseBrowser()) {
+    GURL url = SyncPromoUI::GetNextPageURLForSyncPromoURL(
+        web_ui()->GetWebContents()->GetURL());
+    OpenURLParams params(
+        url, Referrer(), CURRENT_TAB, content::PAGE_TRANSITION_LINK, false);
+    web_ui()->GetWebContents()->OpenURL(params);
+  }
 }
 
 void SyncPromoHandler::HandleInitializeSyncPromo(const base::ListValue* args) {