Check for null on Browser pointer to address crash report.

chrome/browser/ui/search/instant_page.cc

Index: chrome/browser/ui/search/instant_page.cc
diff --git a/chrome/browser/ui/search/instant_page.cc b/chrome/browser/ui/search/instant_page.cc
index e7a52752e499490ad950de8e43869b82e7bd0788..f963d2df5384b3de64a06d3fb05ccd2a5f4fb756 100644
--- a/chrome/browser/ui/search/instant_page.cc
+++ b/chrome/browser/ui/search/instant_page.cc
@@ -300,9 +300,12 @@ void InstantPage::MaybeRemoveMostVisitedItems(
   if (!history::MostVisitedTilesExperiment::IsDontShowOpenURLsEnabled())
     return;
 
-  TabStripModel* tab_strip_model = chrome::FindBrowserWithProfile(
-      profile_,
-      chrome::GetActiveDesktop())->tab_strip_model();
+  Browser* browser = chrome::FindBrowserWithProfile(profile_,
+                                                    chrome::GetActiveDesktop());
+  if (!browser)
+    return;
+
+  TabStripModel* tab_strip_model = browser->tab_strip_model();
   history::TopSites* top_sites = profile_->GetTopSites();
   if (!tab_strip_model || !top_sites) {
     NOTREACHED();