Refactor sync passphrase setup flow and fix passphrase tests

chrome/browser/sync/profile_sync_service_harness.h

Index: chrome/browser/sync/profile_sync_service_harness.h
diff --git a/chrome/browser/sync/profile_sync_service_harness.h b/chrome/browser/sync/profile_sync_service_harness.h
index f3cc6307529e448887f7504b46f5a4b7c30ecde5..f9bfaa09ae453a6e55bfcd88374c19cc56fe2b2a 100644
--- a/chrome/browser/sync/profile_sync_service_harness.h
+++ b/chrome/browser/sync/profile_sync_service_harness.h
@@ -172,6 +172,9 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
     // full sync cycle is not expected to occur.
     WAITING_FOR_SYNC_CONFIGURATION,
 
+    // The sync client needs a passphrase in order to decrypt data.
+    PASSPHRASE_REQUIRED_FOR_DECRYPTION,
+
     // The sync client cannot reach the server.
     SERVER_UNREACHABLE,
 
@@ -216,9 +219,14 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // encrypted to determine if we're done.
   syncable::ModelType waiting_for_encryption_type_;
 
+  // The WaitState in which the sync client currently is. Helps determine what
+  // action to take when RunStateChangeMachine() is called.
   WaitState wait_state_;
 
+  // Sync profile associated with this sync client.
   Profile* profile_;
+
+  // ProfileSyncService object associated with |profile_|.
   ProfileSyncService* service_;
 
   // The harness of the client whose update progress marker we're expecting