Sync: Turn on full history sync by default.

sync/internal_api/public/util/experiments.h

Index: sync/internal_api/public/util/experiments.h
diff --git a/sync/internal_api/public/util/experiments.h b/sync/internal_api/public/util/experiments.h
index a3b874b00f426dfdb42def8c5b74cfe0ca0d6fca..c4b7dd5f286bec63a9e7777215570475015e70a1 100644
--- a/sync/internal_api/public/util/experiments.h
+++ b/sync/internal_api/public/util/experiments.h
@@ -12,8 +12,6 @@ namespace syncer {
 const char kKeystoreEncryptionTag[] = "keystore_encryption";
 const char kKeystoreEncryptionFlag[] = "sync-keystore-encryption";
 const char kAutofillCullingTag[] = "autofill_culling";
-const char kFullHistorySyncTag[] = "history_delete_directives";
-const char kFullHistorySyncFlag[] = "full-history-sync";
 const char kFaviconSyncTag[] = "favicon_sync";
 const char kFaviconSyncFlag[] = "enable-sync-favicons";
 
@@ -21,14 +19,12 @@ const char kFaviconSyncFlag[] = "enable-sync-favicons";
 struct Experiments {
   Experiments() : keystore_encryption(false),
                   autofill_culling(false),
-                  full_history_sync(false),
                   favicon_sync(false),
                   favicon_sync_limit(200) {}
 
   bool Matches(const Experiments& rhs) {
     return (keystore_encryption == rhs.keystore_encryption &&
             autofill_culling == rhs.autofill_culling &&
-            full_history_sync == rhs.full_history_sync &&
             favicon_sync == rhs.favicon_sync &&
             favicon_sync_limit == rhs.favicon_sync_limit);
   }
@@ -39,9 +35,6 @@ struct Experiments {
   // Enable deletion of expired autofill entries (if autofill sync is enabled).
   bool autofill_culling;
 
-  // Enable full history sync (and history delete directives) for this client.
-  bool full_history_sync;
-
   // Enable the favicons sync datatypes (favicon images and favicon tracking).
   bool favicon_sync;