[Sync] Cache encrypted types info in ProfileSyncService

chrome/browser/sync/util/cryptographer.h

Index: chrome/browser/sync/util/cryptographer.h
diff --git a/chrome/browser/sync/util/cryptographer.h b/chrome/browser/sync/util/cryptographer.h
index ac2d4eb90732a5a12a870da1f070abddf2012fda..e78e3f388a31bd7bed28d2b6ded37ab7d4151b01 100644
--- a/chrome/browser/sync/util/cryptographer.h
+++ b/chrome/browser/sync/util/cryptographer.h
@@ -12,6 +12,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "chrome/browser/sync/protocol/nigori_specifics.pb.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 #include "chrome/browser/sync/util/nigori.h"
@@ -43,6 +44,31 @@ struct KeyParams {
 // delayed until after it can be decrypted.
 class Cryptographer {
  public:
+  // All Observer methods are done synchronously, so they're called
+  // under a transaction (since all Cryptographer operations are done
+  // under a transaction).
+  class Observer {
+   public:
+    // Called when the set of encrypted types or the encrypt
+    // everything flag has been changed.  Note that this doesn't
+    // necessarily mean that encryption has completed for the given
+    // types.
+    //
+    // |encrypted_types| will always be a superset of
+    // SensitiveTypes().  If |encrypt_everything| is true,
+    // |encrypted_types| will be the set of all known types.
+    //
+    // Until this function is called, observers can assume that the
+    // set of encrypted types is SensitiveTypes() and that the encrypt
+    // everything flag is false.
+    virtual void OnEncryptedTypesChanged(
+        const syncable::ModelTypeSet& encrypted_types,
+        bool encrypt_everything) = 0;
+
+   protected:
+    virtual ~Observer();
+  };
+
   Cryptographer();
   ~Cryptographer();
 
@@ -54,6 +80,10 @@ class Cryptographer {
     NEEDS_PASSPHRASE
   };
 
+  // Manage observers.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
   // |restored_bootstrap_token| can be provided via this method to bootstrap
   // Cryptographer instance into the ready state (is_ready will be true).
   // It must be a string that was previously built by the
@@ -142,24 +172,30 @@ class Cryptographer {
   // Update the nigori to reflect the current set of encrypted types.
   void UpdateNigoriFromEncryptedTypes(sync_pb::NigoriSpecifics* nigori) const;
 
-  // Setter/getter for whether all current and future datatypes should be
-  // encrypted. Once set you cannot unset without reading from a new nigori
-  // node.
+  // Setter/getter for whether all current and future datatypes should
+  // be encrypted. Once set you cannot unset without reading from a
+  // new nigori node.  set_encrypt_everything() emits a notification
+  // the first time it's called.
   void set_encrypt_everything();
   bool encrypt_everything() const;
 
-  // Set all types in |new_types| as requiring encryption (in addition to the
-  // currently encrypted types). Note: once a type requires encryption it can
-  // never stop requiring encryption without clearing the server data.
-  void SetEncryptedTypes(syncable::ModelTypeSet new_types);
-
   // Return the set of encrypted types.
   syncable::ModelTypeSet GetEncryptedTypes() const;
 
+  // Forwards to SetEncryptedTypes.
+  void SetEncryptedTypesForTest(
+      const syncable::ModelTypeSet& encrypted_types);
+
  private:
   FRIEND_TEST_ALL_PREFIXES(CryptographerTest, PackUnpack);
   typedef std::map<std::string, linked_ptr<const Nigori> > NigoriMap;
 
+  // Changes the set of encrypted types and emits a notification if
+  // necessary.
+  void SetEncryptedTypes(const syncable::ModelTypeSet& encrypted_types);
+
+  void EmitEncryptedTypesChangedNotification();
+
   // Helper method to instantiate Nigori instances for each set of key
   // parameters in |bag| and setting the default encryption key to
   // |default_key_name|.
@@ -173,6 +209,8 @@ class Cryptographer {
   bool PackBootstrapToken(const Nigori* nigori, std::string* pack_into) const;
   Nigori* UnpackBootstrapToken(const std::string& token) const;
 
+  ObserverList<Observer> observers_;
+
   NigoriMap nigoris_;  // The Nigoris we know about, mapped by key name.
   NigoriMap::value_type* default_nigori_;  // The Nigori used for encryption.