[Sync] Rename syncable_prefs to sync_preferences.

Pretty mechanical CL:
- Moved files and ran mass-rename.py
- String-replaced "syncable_prefs" with "sync_preferences"
- String-replaced "SYNCABLE_PREFS_USE_POLICY" with "SYNC_PREFERENCES_USE_POLICY"
- Fixed a couple lints inside sync_preferences
- Ran formatter

BUG=659265
TBR=jam

Review-Url: https://codereview.chromium.org/2459823002
Cr-Commit-Position: refs/heads/master@{#428391}
diff --git a/chrome/browser/prefs/pref_service_syncable_util.h b/chrome/browser/prefs/pref_service_syncable_util.h
index a27a4ca..d4149d9 100644
--- a/chrome/browser/prefs/pref_service_syncable_util.h
+++ b/chrome/browser/prefs/pref_service_syncable_util.h
@@ -8,30 +8,30 @@
 class PrefStore;
 class Profile;
 
-namespace syncable_prefs {
+namespace sync_preferences {
 class PrefServiceSyncable;
 }
 
-// syncable_prefs::PrefServiceSyncable is a PrefService with added integration
+// sync_preferences::PrefServiceSyncable is a PrefService with added integration
 // for sync, and knowledge of how to create an incognito PrefService. For code
 // that does not need to know about the sync integration, you should use only
 // the plain PrefService type.
 //
 // For this reason, Profile does not expose an accessor for the
-// syncable_prefs::PrefServiceSyncable type. Instead, you can use the utilities
-// below to retrieve the syncable_prefs::PrefServiceSyncable (or its incognito
-// version) from a Profile.
-syncable_prefs::PrefServiceSyncable* PrefServiceSyncableFromProfile(
+// sync_preferences::PrefServiceSyncable type. Instead, you can use the
+// utilities below to retrieve the sync_preferences::PrefServiceSyncable (or its
+// incognito version) from a Profile.
+sync_preferences::PrefServiceSyncable* PrefServiceSyncableFromProfile(
     Profile* profile);
-syncable_prefs::PrefServiceSyncable* PrefServiceSyncableIncognitoFromProfile(
+sync_preferences::PrefServiceSyncable* PrefServiceSyncableIncognitoFromProfile(
     Profile* profile);
 
 // Creates an incognito copy of |pref_service| that shares most prefs but uses
 // a fresh non-persistent overlay for the user pref store and an individual
 // extension pref store (to cache the effective extension prefs for incognito
 // windows).
-syncable_prefs::PrefServiceSyncable* CreateIncognitoPrefServiceSyncable(
-    syncable_prefs::PrefServiceSyncable* pref_service,
+sync_preferences::PrefServiceSyncable* CreateIncognitoPrefServiceSyncable(
+    sync_preferences::PrefServiceSyncable* pref_service,
     PrefStore* incognito_extension_pref_store);
 
 #endif  // CHROME_BROWSER_PREFS_PREF_SERVICE_SYNCABLE_UTIL_H_