Allow overriding of X error functions

chrome/browser/chromeos/tab_closeable_state_watcher.cc

Index: chrome/browser/chromeos/tab_closeable_state_watcher.cc
diff --git a/chrome/browser/chromeos/tab_closeable_state_watcher.cc b/chrome/browser/chromeos/tab_closeable_state_watcher.cc
index 536ba9bb8cbaf2499e9c602504938bc9455d51c0..899b88c29db8d4e4b81f128156695064aafd0a3c 100644
--- a/chrome/browser/chromeos/tab_closeable_state_watcher.cc
+++ b/chrome/browser/chromeos/tab_closeable_state_watcher.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
@@ -75,7 +76,8 @@ TabCloseableStateWatcher::TabCloseableStateWatcher()
 
 TabCloseableStateWatcher::~TabCloseableStateWatcher() {
   BrowserList::RemoveObserver(this);
-  DCHECK(tabstrip_watchers_.empty());
+  if (!browser_shutdown::ShuttingDownWithoutClosingBrowsers())
+    DCHECK(tabstrip_watchers_.empty());
 }
 
 bool TabCloseableStateWatcher::CanCloseTab(const Browser* browser) const {