[Sync] Initial support for encrypting any datatype (no UI hookup yet).

chrome/browser/sync/protocol/nigori_specifics.proto

Index: chrome/browser/sync/protocol/nigori_specifics.proto
diff --git a/chrome/browser/sync/protocol/nigori_specifics.proto b/chrome/browser/sync/protocol/nigori_specifics.proto
index 98ee1b704796adc092e855bb3a4727e244d316c1..4e8b8752cfdf6c3f14e86365d60713ef6e2e7045 100644
--- a/chrome/browser/sync/protocol/nigori_specifics.proto
+++ b/chrome/browser/sync/protocol/nigori_specifics.proto
@@ -34,6 +34,18 @@ message NigoriSpecifics {
   // True if |encrypted| is encrypted using a passphrase
   // explicitly set by the user.
   optional bool using_explicit_passphrase = 2;
+  
+  // Booleans corresponding to whether a datatype should be encrypted.
+  // Passwords are always encrypted, so we don't need a field here.
+  optional bool encrypt_bookmarks = 3;
+  optional bool encrypt_preferences = 4;
+  optional bool encrypt_autofill_profile = 5;
+  optional bool encrypt_autofill = 6;
+  optional bool encrypt_themes = 7;
+  optional bool encrypt_typed_urls = 8;
+  optional bool encrypt_extensions = 9;
+  optional bool encrypt_sessions = 10;
+  optional bool encrypt_apps = 11;
 }
 
 extend EntitySpecifics {