--- a/media/webrtc/trunk/webrtc/video_engine/vie_input_manager.cc
+++ b/media/webrtc/trunk/webrtc/video_engine/vie_input_manager.cc
@@ -376,31 +376,36 @@ int32_t ViEInputManager::RegisterObserve
     CriticalSectionScoped cs(observer_cs_.get());
     if (observer_) {
       LOG_F(LS_ERROR) << "Observer already registered.";
       return -1;
     }
     observer_ = observer;
   }
 
+  CriticalSectionScoped cs(device_info_cs_.get());
   if (!GetDeviceInfo())
     return -1;
 
   if (capture_device_info_ != NULL)
     capture_device_info_->RegisterVideoInputFeedBack(*this);
 
   return 0;
 }
 
 int32_t ViEInputManager::DeRegisterObserver() {
-  if (capture_device_info_ != NULL)
-    capture_device_info_->DeRegisterVideoInputFeedBack();
+  {
+    CriticalSectionScoped cs(observer_cs_.get());
+    observer_ = NULL;
+  }
 
-  CriticalSectionScoped cs(observer_cs_.get());
-  observer_ = NULL;
+  CriticalSectionScoped cs(device_info_cs_.get());
+  if (capture_device_info_ != NULL) {
+    capture_device_info_->DeRegisterVideoInputFeedBack();
+  }
   return 0;
 }
 
 ViEInputManagerScoped::ViEInputManagerScoped(
     const ViEInputManager& vie_input_manager)
     : ViEManagerScopedBase(vie_input_manager) {
 }