Merge Chromium src@r53293

Change-Id: Ia79acf8670f385cee48c45b0a75371d8e950af34

1 files changed, 69 insertions, 0 deletions

diff --git a/chrome/browser/sync/glue/change_processor.h b/chrome/browser/sync/glue/change_processor.h
new file mode 100644
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--- /dev/null
+++ b/chrome/browser/sync/glue/change_processor.h
@@ -0,0 +1,69 @@
+// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SYNC_GLUE_CHANGE_PROCESSOR_H_
+#define CHROME_BROWSER_SYNC_GLUE_CHANGE_PROCESSOR_H_
+
+#include "chrome/browser/sync/engine/syncapi.h"
+#include "chrome/browser/sync/glue/sync_backend_host.h"
+
+class Profile;
+
+namespace browser_sync {
+
+class ModelAssociator;
+class UnrecoverableErrorHandler;
+
+// An interface used to apply changes from the sync model to the browser's
+// native model.  This does not currently distinguish between model data types.
+class ChangeProcessor {
+ public:
+  explicit ChangeProcessor(UnrecoverableErrorHandler* error_handler)
+      : running_(false), error_handler_(error_handler), share_handle_(NULL) {}
+  virtual ~ChangeProcessor();
+
+  // Call when the processor should accept changes from either provided model
+  // and apply them to the other.  Both the chrome model and sync_api are
+  // expected to be initialized and loaded.  You must have set a valid
+  // ModelAssociator and UnrecoverableErrorHandler before using this method,
+  // and the two models should be associated w.r.t the ModelAssociator provided.
+  // It is safe to call Start again after previously Stop()ing the processor.
+  // Subclasses can extract their associated chrome model from |profile| in
+  // |StartImpl|.
+  void Start(Profile* profile, sync_api::UserShare* share_handle);
+  void Stop();
+  virtual bool IsRunning() const { return running_; }
+
+  // Changes have been applied to the backend model and are ready to be
+  // applied to the frontend model. See syncapi.h for detailed instructions on
+  // how to interpret and process |changes|.
+  virtual void ApplyChangesFromSyncModel(
+      const sync_api::BaseTransaction* trans,
+      const sync_api::SyncManager::ChangeRecord* changes,
+      int change_count) = 0;
+
+ protected:
+  // These methods are invoked by Start() and Stop() to do
+  // implementation-specific work.
+  virtual void StartImpl(Profile* profile) = 0;
+  virtual void StopImpl() = 0;
+
+  bool running() { return running_; }
+  UnrecoverableErrorHandler* error_handler() { return error_handler_; }
+  sync_api::UserShare* share_handle() { return share_handle_; }
+
+ private:
+  bool running_;  // True if we have been told it is safe to process changes.
+  UnrecoverableErrorHandler* error_handler_;  // Guaranteed to outlive us.
+
+  // The sync model we are processing changes from. Non-NULL when |running_| is
+  // true.
+  sync_api::UserShare* share_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChangeProcessor);
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_CHANGE_PROCESSOR_H_