Allow GCF installation on machine with old IE 7 installs.

chrome_frame/chrome_tab.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // chrome_tab.cc : Implementation of DLL Exports.
 
 // Need to include this before the ATL headers below.
 #include "chrome_frame/chrome_tab.h"
 
 #include <atlsecurity.h>
@@ skipping 594 matching lines @@
   return ChromeFrameActivex::UpdateRegistry(reg);
 }
 
 HRESULT RegisterElevationPolicy(bool reg, bool is_system) {
   HRESULT hr = S_OK;
   if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
     // Register the elevation policy. This must succeed for Chrome Frame to
     // be able launch Chrome when running in low-integrity IE.
     hr = _AtlModule.UpdateRegistryFromResourceS(IDR_CHROMEFRAME_ELEVATION, reg);
     if (SUCCEEDED(hr)) {
-      hr = RefreshElevationPolicy();
+      // Ignore failures since old versions of IE 7 (e.g., 7.0.6000.16386, which
+      // shipped with Vista RTM) do not export IERefreshElevationPolicy.
+      RefreshElevationPolicy();
     }
   }
   return hr;
 }
 
 HRESULT RegisterProtocol(bool reg, bool is_system) {
   return _AtlModule.UpdateRegistryFromResourceS(IDR_CHROMEPROTOCOL, reg);
 }
 
 HRESULT RegisterBhoClsid(bool reg, bool is_system) {
@@ skipping 290 matching lines @@
   HRESULT hr = CustomRegistration(ALL, FALSE, false);
   return hr;
 }
 
 // Object entries go here instead of with each object, so that we can move
 // the objects to a lib. Also reduces magic.
 OBJECT_ENTRY_AUTO(CLSID_ChromeFrameBHO, Bho)
 OBJECT_ENTRY_AUTO(__uuidof(ChromeActiveDocument), ChromeActiveDocument)
 OBJECT_ENTRY_AUTO(__uuidof(ChromeFrame), ChromeFrameActivex)
 OBJECT_ENTRY_AUTO(__uuidof(ChromeProtocol), ChromeProtocol)