Make sure that pointer to the ExtensionsService is valid in the extensions infobars.

chrome/browser/extensions/crashed_extension_infobar.h

Index: chrome/browser/extensions/crashed_extension_infobar.h
diff --git a/chrome/browser/extensions/crashed_extension_infobar.h b/chrome/browser/extensions/crashed_extension_infobar.h
index 4a4e625115a29caf09cc62e10538b1318b74bd4a..6db12ba7fb47dcce0c7bf6dadb7f54cdf05b7d54 100644
--- a/chrome/browser/extensions/crashed_extension_infobar.h
+++ b/chrome/browser/extensions/crashed_extension_infobar.h
@@ -24,6 +24,7 @@ class CrashedExtensionInfoBarDelegate : public ConfirmInfoBarDelegate {
   CrashedExtensionInfoBarDelegate(TabContents* tab_contents,
                                   ExtensionsService* extensions_service,
                                   const Extension* extension);
+  ~CrashedExtensionInfoBarDelegate();
 
   // ConfirmInfoBarDelegate
   virtual std::wstring GetMessageText() const;
@@ -35,7 +36,7 @@ class CrashedExtensionInfoBarDelegate : public ConfirmInfoBarDelegate {
   virtual bool Accept();
 
  private:
-  ExtensionsService* extensions_service_;
+  scoped_refptr<ExtensionsService> extensions_service_;
 
   const std::string extension_id_;
   const std::string extension_name_;