Resubmit r133740: Fix homepage migration for users who never changed their settings.

chrome/browser/prefs/session_startup_pref.cc

 // 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.
 
 #include "chrome/browser/prefs/session_startup_pref.h"
 
 #include <string>
 
 #include "base/values.h"
 #include "chrome/browser/net/url_fixer_upper.h"
@@ skipping 17 matching lines @@
 // Converts a SessionStartupPref::Type to an integer written to prefs.
 int TypeToPrefValue(SessionStartupPref::Type type) {
   switch (type) {
     case SessionStartupPref::LAST: return SessionStartupPref::kPrefValueLast;
     case SessionStartupPref::URLS: return SessionStartupPref::kPrefValueURLs;
     default:                       return SessionStartupPref::kPrefValueNewTab;
   }
 }
 
 void SetNewURLList(PrefService* prefs) {
-  ListValue new_url_pref_list;
-  StringValue* home_page = new StringValue(prefs->GetString(prefs::kHomePage));
-  new_url_pref_list.Append(home_page);
-  prefs->Set(prefs::kURLsToRestoreOnStartup, new_url_pref_list);
+  if (prefs->IsUserModifiablePreference(prefs::kURLsToRestoreOnStartup)) {
+    base::ListValue new_url_pref_list;
+    base::StringValue* home_page =
+        new base::StringValue(prefs->GetString(prefs::kHomePage));
+    new_url_pref_list.Append(home_page);
+    prefs->Set(prefs::kURLsToRestoreOnStartup, new_url_pref_list);
+  }
 }
 
 void URLListToPref(const base::ListValue* url_list, SessionStartupPref* pref) {
   pref->urls.clear();
   for (size_t i = 0; i < url_list->GetSize(); ++i) {
     std::string url_text;
     if (url_list->GetString(i, &url_text)) {
       GURL fixed_url = URLFixerUpper::FixupURL(url_text, "");
       pref->urls.push_back(fixed_url);
     }
   }
 }
 
 }  // namespace
 
 // static
 void SessionStartupPref::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterIntegerPref(prefs::kRestoreOnStartup,
                              TypeToPrefValue(GetDefaultStartupType()),
                              PrefService::SYNCABLE_PREF);
   prefs->RegisterListPref(prefs::kURLsToRestoreOnStartup,
                           PrefService::SYNCABLE_PREF);
+  prefs->RegisterBooleanPref(prefs::kRestoreOnStartupMigrated,
+                             false,
+                             PrefService::UNSYNCABLE_PREF);
 }
 
 // static
 SessionStartupPref::Type SessionStartupPref::GetDefaultStartupType() {

[Tyler Breisacher (Chromium), 2012/04/24 21:27:22]

Notice that 'DEFAULT' is not always the default. The migration at line 178-179
now only happens if it is.

 #if defined(OS_CHROMEOS)
   SessionStartupPref::Type type = SessionStartupPref::LAST;
 #else
   SessionStartupPref::Type type = SessionStartupPref::DEFAULT;
 #endif
 
 #if defined(OS_MACOSX)
   // Use Lion's system preference, if it is set.
   if (restore_utils::IsWindowRestoreEnabled())
     type = SessionStartupPref::LAST;
@@ skipping 35 matching lines @@
 
 // static
 SessionStartupPref SessionStartupPref::GetStartupPref(Profile* profile) {
   DCHECK(profile);
   return GetStartupPref(profile->GetPrefs());
 }
 
 // static
 SessionStartupPref SessionStartupPref::GetStartupPref(PrefService* prefs) {
   DCHECK(prefs);
+
+  MigrateIfNecessary(prefs);
+
   SessionStartupPref pref(
       PrefValueToType(prefs->GetInteger(prefs::kRestoreOnStartup)));
 
-  // Migrate from "Open the home page" to "Open the following URLs". If the user
-  // had the "Open the homepage" option selected, then we need to switch them to
-  // "Open the following URLs" and set the list of URLs to a list containing
-  // just the user's homepage.
-  if (pref.type == SessionStartupPref::HOMEPAGE) {
-    prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueURLs);
-    pref.type = SessionStartupPref::URLS;
-    SetNewURLList(prefs);
-  }
-
   // Always load the urls, even if the pref type isn't URLS. This way the
   // preferences panels can show the user their last choice.
   const ListValue* url_list = prefs->GetList(prefs::kURLsToRestoreOnStartup);
   URLListToPref(url_list, &pref);
 
   return pref;
 }
 
 // static
+void SessionStartupPref::MigrateIfNecessary(PrefService* prefs) {
+  DCHECK(prefs);
+
+  if (!prefs->GetBoolean(prefs::kRestoreOnStartupMigrated)) {
+    // Read existing values
+    const base::Value* homepage_is_new_tab_page_value =
+        prefs->GetUserPrefValue(prefs::kHomePageIsNewTabPage);
+    bool homepage_is_new_tab_page = true;
+    if (homepage_is_new_tab_page_value)
+      homepage_is_new_tab_page_value->GetAsBoolean(&homepage_is_new_tab_page);
+
+    const base::Value* restore_on_startup_value =
+        prefs->GetUserPrefValue(prefs::kRestoreOnStartup);
+    int restore_on_startup = -1;
+    if (restore_on_startup_value)
+      restore_on_startup_value->GetAsInteger(&restore_on_startup);
+
+    // If restore_on_startup has the deprecated value kPrefValueHomePage,
+    // migrate it to open the homepage on startup. If 'homepage is NTP' is set,
+    // that means just opening the NTP. If not, it means opening a one-item URL
+    // list containing the homepage.
+    if (restore_on_startup == kPrefValueHomePage) {
+      if (homepage_is_new_tab_page) {
+        prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueNewTab);
+      } else {
+        prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueURLs);
+        SetNewURLList(prefs);
+      }
+    } else if (!restore_on_startup_value && !homepage_is_new_tab_page &&
+               GetDefaultStartupType() == DEFAULT) {
+      // kRestoreOnStartup was never set by the user, but the homepage was set.
+      // Migrate to the list of URLs. (If restore_on_startup was never set,
+      // and homepage_is_new_tab_page is true, no action is needed. The new
+      // default value is "open the new tab page" which is what we want.)
+      prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueURLs);
+      SetNewURLList(prefs);
+    }
+
+    prefs->SetBoolean(prefs::kRestoreOnStartupMigrated, true);
+  }
+}
+
+// static
 bool SessionStartupPref::TypeIsManaged(PrefService* prefs) {
   DCHECK(prefs);
   const PrefService::Preference* pref_restore =
       prefs->FindPreference(prefs::kRestoreOnStartup);
   DCHECK(pref_restore);
   return pref_restore->IsManaged();
 }
 
 // static
 bool SessionStartupPref::URLsAreManaged(PrefService* prefs) {
@@ skipping 45 matching lines @@
   CHECK(prefs_watcher->GetBackupForPref(
             prefs::kURLsToRestoreOnStartup)->GetAsList(&url_list));
   URLListToPref(url_list, &backup_pref);
 
   return backup_pref;
 }
 
 SessionStartupPref::SessionStartupPref(Type type) : type(type) {}
 
 SessionStartupPref::~SessionStartupPref() {}