Revamp the MigrateBrowserPrefs and MigrateUserPrefs code.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 451d1cbfacd30282be6c18f7e08c6e1dd3a49561..deeb05bfd5fb107c5e15c21da19176de52c5aa0e 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -376,18 +376,10 @@ const char kPromptForDownload[] = "download.prompt_for_download";
 // A boolean pref set to true if we're using Link Doctor error pages.
 const char kAlternateErrorPagesEnabled[] = "alternate_error_pages.enabled";
 
-// OBSOLETE: new pref now stored with user prefs instead of profile, as
-// kDnsPrefetchingStartupList.
-const char kDnsStartupPrefetchList[] = "StartupDNSPrefetchList";
-
 // An adaptively identified list of domain names to be pre-fetched during the
 // next startup, based on what was actually needed during this startup.
 const char kDnsPrefetchingStartupList[] = "dns_prefetching.startup_list";
 
-// OBSOLETE: new pref now stored with user prefs instead of profile, as
-// kDnsPrefetchingHostReferralList.
-const char kDnsHostReferralList[] = "HostReferralList";
-
 // A list of host names used to fetch web pages, and their commonly used
 // sub-resource hostnames (and expected latency benefits from pre-resolving, or
 // preconnecting to, such sub-resource hostnames).
@@ -421,16 +413,6 @@ const char kLastPolicyCheckTime[] = "policy.last_policy_check_time";
 const char kInstantUIZeroSuggestUrlPrefix[] =
     "instant_ui.zero_suggest_url_prefix";
 
-// Used to migrate preferences from local state to user preferences to
-// enable multiple profiles.
-// BITMASK with possible values (see browser_prefs.cc for enum):
-// 0: No preferences migrated.
-// 1: DNS preferences migrated: kDnsPrefetchingStartupList and HostReferralList
-// 2: Browser window preferences migrated: kDevToolsSplitLocation and
-//    kBrowserWindowPlacement
-const char kMultipleProfilePrefMigration[] =
-    "local_state.multiple_profile_prefs_version";
-
 // A boolean pref set to true if prediction of network actions is allowed.
 // Actions include DNS prefetching, TCP and SSL preconnection, prerendering
 // of web pages, and resource prefetching.