ChromeFrame tabs would hang at times while closing. This would randomly occur...

chrome_frame/chrome_frame_activex_base.h

Index: chrome_frame/chrome_frame_activex_base.h
===================================================================
--- chrome_frame/chrome_frame_activex_base.h	(revision 52332)
+++ chrome_frame/chrome_frame_activex_base.h	(working copy)
@@ -361,6 +361,43 @@
     return true;
   }
 
+  // IOleInPlaceObject overrides.
+  STDMETHOD(InPlaceDeactivate)(void) {
+    static UINT onload_handlers_done_msg =
+        RegisterWindowMessage(L"ChromeFrame_OnloadHandlersDone");
+
+    if (m_bInPlaceActive && IsWindow() && IsValid()) {
+      static const int kChromeFrameUnloadEventTimerId = 0xdeadbeef;
+      static const int kChromeFrameUnloadEventTimeout = 1000;
+
+      // To prevent us from indefinitely waiting for an acknowledgement from
+      // Chrome indicating that unload handlers have been run, we set a 1
+      // second timer and exit the loop when it fires.
+      ::SetTimer(m_hWnd, kChromeFrameUnloadEventTimerId,
+                 kChromeFrameUnloadEventTimeout, NULL);
+
+      automation_client_->RunUnloadHandlers(m_hWnd, onload_handlers_done_msg);
+
+      MSG msg = {0};
+      while (GetMessage(&msg, NULL, 0, 0)) {
+        if (msg.message == onload_handlers_done_msg &&
+            msg.hwnd == m_hWnd) {
+          break;
+        }
+
+        if (msg.message == WM_TIMER &&
+            msg.wParam == kChromeFrameUnloadEventTimerId) {
+          break;
+        }
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+      }
+
+      ::KillTimer(m_hWnd, kChromeFrameUnloadEventTimerId);
+    }
+    return IOleInPlaceObjectWindowlessImpl<T>::InPlaceDeactivate();
+  }
+
  protected:
   virtual void GetProfilePath(const std::wstring& profile_name,
                               FilePath* profile_path) {