[Sync] Fix sync scheduler/session logic determining successful commands.

sync/sessions/sync_session.h

Index: sync/sessions/sync_session.h
diff --git a/sync/sessions/sync_session.h b/sync/sessions/sync_session.h
index 1dfe78cfd1cb3fe20577360aa8b35e014a29a936..e963e4a3278351a116f6bd23ddb6a65425a736ba 100644
--- a/sync/sessions/sync_session.h
+++ b/sync/sessions/sync_session.h
@@ -112,7 +112,7 @@ class SyncSession {
   // engine again.
   bool HasMoreToSync() const;
 
-  // Returns true if there we did not detect any errors in this session.
+  // Returns true if we completely ran the session without errors.
   //
   // There are many errors that could prevent a sync cycle from succeeding.
   // These include invalid local state, inability to contact the server,
@@ -128,6 +128,10 @@ class SyncSession {
   // since the last call to SyncShare.
   bool Succeeded() const;
 
+  // Returns true if we reached the server successfully and the server did not
+  // return any error codes. Returns false if no connection was attempted.
+  bool SuccessfullyReachedServer() const;
+
   // Collects all state pertaining to how and why |s| originated and unions it
   // with corresponding state in |this|, leaving |s| unchanged.  Allows |this|
   // to take on the responsibilities |s| had (e.g. certain data types) in the
@@ -176,6 +180,9 @@ class SyncSession {
   // Returns the set of enabled groups that have verified updates.
   std::set<ModelSafeGroup> GetEnabledGroupsWithVerifiedUpdates() const;
 
+  // Mark the session has having finished all the sync steps it needed.
+  void SetFinished();
+
  private:
   // Extend the encapsulation boundary to utilities for internal member
   // assignments. This way, the scope of these actions is explicit, they can't
@@ -213,6 +220,10 @@ class SyncSession {
   // |routing_info_|.
   std::set<ModelSafeGroup> enabled_groups_;
 
+  // Whether this session has reached its last step or not. Gets reset on each
+  // new cycle (via PrepareForAnotherSyncCycle).
+  bool finished_;
+
   DISALLOW_COPY_AND_ASSIGN(SyncSession);
 };