Fix prefs registration for BrowserInstantController.

chrome/browser/ui/browser_instant_controller.cc

Index: chrome/browser/ui/browser_instant_controller.cc
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index 582ae88a9009ee2429c033d94ebfc861278d625f..b87b26d6017523534ed6c8a2845cf572399bb93e 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -28,13 +28,6 @@
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/sys_color_change_listener.h"
 
-namespace {
-const char* GetInstantPrefName(Profile* profile) {
-  return chrome::search::IsInstantExtendedAPIEnabled(profile) ?
-      prefs::kInstantExtendedEnabled : prefs::kInstantEnabled;
-}
-}
-
 namespace chrome {
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -46,15 +39,15 @@ BrowserInstantController::BrowserInstantController(Browser* browser)
                chrome::search::IsInstantExtendedAPIEnabled(profile())),
       instant_unload_handler_(browser),
       initialized_theme_info_(false) {
-  profile_pref_registrar_.Init(profile()->GetPrefs());
-  profile_pref_registrar_.Add(
-      GetInstantPrefName(profile()),
-      base::Bind(&BrowserInstantController::ResetInstant,
-                 base::Unretained(this)));
-  profile_pref_registrar_.Add(
-      prefs::kSearchSuggestEnabled,
-      base::Bind(&BrowserInstantController::ResetInstant,
-                 base::Unretained(this)));
+  PrefService* prefs = profile()->GetPrefs();
+
+  profile_pref_registrar_.Init(prefs);
+  base::Closure reset_instant = base::Bind(
+      &BrowserInstantController::ResetInstant,
+      base::Unretained(this));
+  profile_pref_registrar_.Add(prefs::kInstantEnabled, reset_instant);
+  profile_pref_registrar_.Add(prefs::kInstantExtendedEnabled, reset_instant);
+  profile_pref_registrar_.Add(prefs::kSearchSuggestEnabled, reset_instant);
   ResetInstant();
   browser_->search_model()->AddObserver(this);
 
@@ -71,14 +64,26 @@ BrowserInstantController::~BrowserInstantController() {
 }
 
 bool BrowserInstantController::IsInstantEnabled(Profile* profile) {
-  return profile && !profile->IsOffTheRecord() && profile->GetPrefs() &&
-         profile->GetPrefs()->GetBoolean(GetInstantPrefName(profile));
+  if (!profile || profile->IsOffTheRecord())
+    return false;
+
+  PrefService* prefs = profile->GetPrefs();
+  if (!prefs)
+    return false;
+
+  if (!chrome::search::IsInstantExtendedAPIEnabled(profile) ||
+      (search::GetInstantExtendedDefaultSetting() ==
+       search::INSTANT_USE_EXISTING &&
+       prefs->FindPreference(
+           prefs::kInstantExtendedEnabled)->IsDefaultValue())) {
+    return prefs->GetBoolean(prefs::kInstantEnabled);
+  } else {
+    return prefs->GetBoolean(prefs::kInstantExtendedEnabled);
+  }
 }
 
 void BrowserInstantController::RegisterUserPrefs(
-    PrefService* prefs,
     PrefRegistrySyncable* registry) {
-  // TODO(joi): Get rid of the need for PrefService param above.
   registry->RegisterBooleanPref(prefs::kInstantConfirmDialogShown, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterBooleanPref(prefs::kInstantEnabled, false,
@@ -89,9 +94,10 @@ void BrowserInstantController::RegisterUserPrefs(
     case search::INSTANT_DEFAULT_ON:
       instant_extended_default = true;
       break;
+    // In the INSTANT_USE_EXISTING case, the kInstantExtendedEnabled
+    // preference, if it still has a default value, is set to the
+    // value of kInstantEnabled in the constructor of this class.
     case search::INSTANT_USE_EXISTING:
-      instant_extended_default = prefs->GetBoolean(prefs::kInstantEnabled);
-      break;
     case search::INSTANT_DEFAULT_OFF:
       instant_extended_default = false;
       break;