1 files changed, 3 insertions, 0 deletions
diff --git a/chrome_frame/chrome_frame_automation.cc b/chrome_frame/chrome_frame_automation.cc
index 6f31bf7..908df61d 100644
--- a/chrome_frame/chrome_frame_automation.cc
+++ b/chrome_frame/chrome_frame_automation.cc
@@ -51,10 +51,12 @@ class ChromeFrameAutomationProxyImpl::TabProxyNotificationMessageFilter
   }
 
   void AddTabProxy(AutomationHandle tab_proxy) {
+    AutoLock lock(lock_);
     tabs_list_.push_back(tab_proxy);
   }
 
   void RemoveTabProxy(AutomationHandle tab_proxy) {
+    AutoLock lock(lock_);
     tabs_list_.remove(tab_proxy);
   }
 
@@ -92,6 +94,7 @@ class ChromeFrameAutomationProxyImpl::TabProxyNotificationMessageFilter
  private:
   AutomationHandleTracker* tracker_;
   std::list<AutomationHandle> tabs_list_;
+  Lock lock_;
 };
 
 class ChromeFrameAutomationProxyImpl::CFMsgDispatcher