Ensure we don't crash if user navigates back from NTP to Chrome sign-in page before it has fully lo…

chrome/browser/ui/sync/one_click_signin_helper.cc

Index: chrome/browser/ui/sync/one_click_signin_helper.cc
diff --git a/chrome/browser/ui/sync/one_click_signin_helper.cc b/chrome/browser/ui/sync/one_click_signin_helper.cc
index a39c0d7be7c15802ba3983ed998f2bb1396eab9e..88dbd38dd009d1149b411a0622f8008e32fa306b 100644
--- a/chrome/browser/ui/sync/one_click_signin_helper.cc
+++ b/chrome/browser/ui/sync/one_click_signin_helper.cc
@@ -470,8 +470,9 @@ class CurrentHistoryCleaner : public content::WebContentsObserver {
 
   // content::WebContentsObserver:
   virtual void WebContentsDestroyed(content::WebContents* contents) OVERRIDE;
-  virtual void DidStopLoading(
-      content::RenderViewHost* render_view_host) OVERRIDE;
+  virtual void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) OVERRIDE;
 
  private:
   scoped_ptr<content::WebContents> contents_;
@@ -489,13 +490,14 @@ CurrentHistoryCleaner::CurrentHistoryCleaner(content::WebContents* contents)
 CurrentHistoryCleaner::~CurrentHistoryCleaner() {
 }
 
-void CurrentHistoryCleaner::DidStopLoading(
-    content::RenderViewHost* render_view_host) {
+void CurrentHistoryCleaner::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
   content::NavigationController* nc = &web_contents()->GetController();
   // Have to wait until something else gets added to history before removal.
   if (history_index_to_remove_ < nc->GetLastCommittedEntryIndex()) {
-    nc->RemoveEntryAtIndex(history_index_to_remove_);
-    delete this;  // Success.
+    if (nc->RemoveEntryAtIndex(history_index_to_remove_))
+      delete this;  // Success.
   }
 }