Refactor sync passphrase setup flow and fix passphrase tests

chrome/browser/sync/profile_sync_service.h

Index: chrome/browser/sync/profile_sync_service.h
diff --git a/chrome/browser/sync/profile_sync_service.h b/chrome/browser/sync/profile_sync_service.h
index 05aa410b3da09174ed2ff9a1d4deae2c9fadef1e..de6ea7e289a2fa56285083a5a2d181777672e7c0 100644
--- a/chrome/browser/sync/profile_sync_service.h
+++ b/chrome/browser/sync/profile_sync_service.h
@@ -195,7 +195,7 @@ class ProfileSyncService : public browser_sync::SyncFrontend,
   virtual void OnClearServerDataFailed();
   virtual void OnClearServerDataTimeout();
   virtual void OnClearServerDataSucceeded();
-  virtual void OnPassphraseRequired(bool for_decryption);
+  virtual void OnPassphraseRequired(sync_api::PassphraseRequiredReason reason);
   virtual void OnPassphraseAccepted();
   virtual void OnEncryptionComplete(
       const syncable::ModelTypeSet& encrypted_types);
@@ -286,8 +286,8 @@ class ProfileSyncService : public browser_sync::SyncFrontend,
     return observed_passphrase_required_;
   }
 
-  bool passphrase_required_for_decryption() const {
-    return passphrase_required_for_decryption_;
+  sync_api::PassphraseRequiredReason passphrase_required_reason() const {
+    return passphrase_required_reason_;
   }
 
   // Returns a user-friendly string form of last synced time (in minutes).
@@ -514,8 +514,9 @@ class ProfileSyncService : public browser_sync::SyncFrontend,
   bool observed_passphrase_required_;
 
   // Was the last SYNC_PASSPHRASE_REQUIRED notification sent because it
-  // was required for decryption?
-  bool passphrase_required_for_decryption_;
+  // was required for encryption, decryption with a cached passphrase, or
+  // because a new passphrase is required?
+  sync_api::PassphraseRequiredReason passphrase_required_reason_;
 
   // Is the user in a passphrase migration?
   bool passphrase_migration_in_progress_;