Instant: Use only one hidden WebContents per profile.

chrome/browser/ui/search/search.cc

 // Copyright 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.
 
 #include "chrome/browser/ui/search/search.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
@@ skipping 300 matching lines @@
 }
 
 void RegisterUserPrefs(PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(prefs::kInstantConfirmDialogShown, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterBooleanPref(prefs::kInstantEnabled, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
   // This default is overridden by SetInstantExtendedPrefDefault().
   registry->RegisterBooleanPref(prefs::kInstantExtendedEnabled, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
+
+  // TODO(jered): Remove this.
+  registry->RegisterStringPref(prefs::kInstantUIZeroSuggestUrlPrefix, "",
+                               PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 const char* GetInstantPrefName() {
   return IsInstantExtendedAPIEnabled() ? prefs::kInstantExtendedEnabled :
                                          prefs::kInstantEnabled;
 }
 
 bool IsInstantPrefEnabled(Profile* profile) {
   if (!profile || profile->IsOffTheRecord())
     return false;
@@ skipping 190 matching lines @@
   GURL::Replacements replacements;
   replacements.SetSchemeStr(search_scheme);
   replacements.SetHostStr(search_host);
   replacements.SetPortStr(search_port);
   replacements.SetPathStr(search_path);
   return instant_url.ReplaceComponents(replacements);
 }
 
 }  // namespace search
 }  // namespace chrome