Relanding this as this did not fix the chromiumos breakage.

chrome/browser/prefs/pref_member.cc

Index: chrome/browser/prefs/pref_member.cc
===================================================================
--- chrome/browser/prefs/pref_member.cc	(revision 150400)
+++ chrome/browser/prefs/pref_member.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -35,7 +35,8 @@
   prefs_ = prefs;
   pref_name_ = pref_name;
   // Check that the preference is registered.
-  DCHECK(prefs_->FindPreference(pref_name_.c_str()));
+  DCHECK(prefs_->FindPreference(pref_name_.c_str()))
+      << pref_name << " not registered.";
 
   // Add ourselves as a pref observer so we can keep our local value in sync.
   prefs_->AddPrefObserver(pref_name, this);
Property changes on: chrome\browser\prefs\pref_member.cc
___________________________________________________________________
Added: svn:mergeinfo