[Sync] Refactor non-frontend DTC to handle new API properly.

chrome/browser/sync/glue/generic_change_processor.h

Index: chrome/browser/sync/glue/generic_change_processor.h
diff --git a/chrome/browser/sync/glue/generic_change_processor.h b/chrome/browser/sync/glue/generic_change_processor.h
index 1afe628c87340e2c320d1df0b6e9c0bb0edd5979..b43f00e16cd7412a83f1d36f5160fa5fcef425b2 100644
--- a/chrome/browser/sync/glue/generic_change_processor.h
+++ b/chrome/browser/sync/glue/generic_change_processor.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/threading/non_thread_safe.h"
 #include "chrome/browser/sync/api/sync_change_processor.h"
 #include "chrome/browser/sync/glue/change_processor.h"
 
@@ -26,13 +27,18 @@ namespace browser_sync {
 // handles all interaction with the sync api, both translating pushes from the
 // local service into transactions and receiving changes from the sync model,
 // which then get converted into SyncChange's and sent to the local service.
+//
+// As a rule, the GenericChangeProcessor is not thread safe, and should only
+// be used on the same thread in which it was created.
 class GenericChangeProcessor : public ChangeProcessor,
-                               public SyncChangeProcessor {
+                               public SyncChangeProcessor,
+                               public base::NonThreadSafe {
  public:
-  GenericChangeProcessor(SyncableService* local_service,
-                         UnrecoverableErrorHandler* error_handler,
+  // Create a change processor and connect it to the syncer.
+  GenericChangeProcessor(UnrecoverableErrorHandler* error_handler,
+                         SyncableService* local_service,
                          sync_api::UserShare* user_share);
-  virtual ~GenericChangeProcessor();
+  virtual ~GenericChangeProcessor() OVERRIDE;
 
   // ChangeProcessor interface.
   // Build and store a list of all changes into |syncer_changes_|.
@@ -53,15 +59,24 @@ class GenericChangeProcessor : public ChangeProcessor,
                                        SyncDataList* current_sync_data);
 
   // Generic versions of AssociatorInterface methods. Called by
-  // SyncableServiceAdapter.
-  bool SyncModelHasUserCreatedNodes(syncable::ModelType type,
-                                    bool* has_nodes);
-  bool CryptoReadyIfNecessary(syncable::ModelType type);
+  // SyncableServiceAdapter or the DataTypeController.
+  virtual bool SyncModelHasUserCreatedNodes(syncable::ModelType type,
+                                            bool* has_nodes);
+  virtual bool CryptoReadyIfNecessary(syncable::ModelType type);
+
  protected:
+  // Create an uninitialized change processor.
+  explicit GenericChangeProcessor(UnrecoverableErrorHandler* error_handler);
+
+  virtual void set_local_service(SyncableService* local_service);
+  virtual SyncableService* local_service() const;
+  virtual void set_share_handle(sync_api::UserShare* user_share);
+
   // ChangeProcessor interface.
-  virtual void StartImpl(Profile* profile) OVERRIDE;  // Not implemented.
-  virtual void StopImpl() OVERRIDE;  // Not implemented.
-  virtual sync_api::UserShare* share_handle() OVERRIDE;
+  virtual void StartImpl(Profile* profile) OVERRIDE;           // Does nothing.
+  virtual void StopImpl() OVERRIDE;                            // Does nothing.
+  virtual sync_api::UserShare* share_handle() const OVERRIDE;
+
  private:
   // The SyncableService this change processor will forward changes on to.
   SyncableService* local_service_;
@@ -77,7 +92,9 @@ class GenericChangeProcessor : public ChangeProcessor,
   // listening to changes (the local_service_ will be interacting with us
   // when it starts up). As such we can't wait until Start(_) has been called,
   // and have to keep a local pointer to the user_share.
-  sync_api::UserShare* user_share_;
+  sync_api::UserShare* share_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(GenericChangeProcessor);
 };
 
 }  // namespace browser_sync