Reland 1: "mac: Allow Chrome to hand off its active URL to other devices."

components/handoff/handoff_manager.h

Index: components/handoff/handoff_manager.h
diff --git a/components/handoff/handoff_manager.h b/components/handoff/handoff_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..8b28a35b7a31973aea0d6d0d455b4783a59361e5
--- /dev/null
+++ b/components/handoff/handoff_manager.h
@@ -0,0 +1,32 @@
+// Copyright 2014 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 COMPONENTS_HANDOFF_HANDOFF_MANAGER_H_
+#define COMPONENTS_HANDOFF_HANDOFF_MANAGER_H_
+
+#include <Foundation/Foundation.h>
+
+#include "base/mac/objc_property_releaser.h"
+#include "url/gurl.h"
+
+@class NSUserActivity;
+
+// Maintains all of the state relevant to the Handoff feature. Allows Chrome to
+// hand off the current active URL to other devices.
+@interface HandoffManager : NSObject {
+ @private
+  base::mac::ObjCPropertyReleaser _propertyReleaser_HandoffManager;
+
+  GURL _activeURL;
+  NSUserActivity* _userActivity;
+}
+
+// The active URL is defined as the URL of the most recently accessed tab. This
+// method should be called any time the active URL might have changed. This
+// method is idempotent.
+- (void)updateActiveURL:(const GURL&)url;
+
+@end
+
+#endif  // COMPONENTS_HANDOFF_HANDOFF_MANAGER_H_