[Sync] Fix namespaces for the sync_sessions component.

chrome/browser/sync/glue/synced_window_delegate_android.h

 // Copyright (c) 2012 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_SYNCED_WINDOW_DELEGATE_ANDROID_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNCED_WINDOW_DELEGATE_ANDROID_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "components/sessions/core/session_id.h"
 #include "components/sync_sessions/synced_window_delegate.h"
 
 class TabModel;
 
+namespace sync_sessions {
+class SyncedTabDelegate;
+}  // namespace sync_sessions
+
 namespace browser_sync {
 
-class SyncedTabDelegate;
-
-class SyncedWindowDelegateAndroid : public browser_sync::SyncedWindowDelegate {
+class SyncedWindowDelegateAndroid : public sync_sessions::SyncedWindowDelegate {
  public:
   explicit SyncedWindowDelegateAndroid(TabModel* tab_model);
   ~SyncedWindowDelegateAndroid() override;
 
-  // browser_sync::SyncedWindowDelegate implementation.
-
+  // sync_sessions::SyncedWindowDelegate implementation.
   bool HasWindow() const override;
   SessionID::id_type GetSessionId() const override;
   int GetTabCount() const override;
   int GetActiveIndex() const override;
   bool IsApp() const override;
   bool IsTypeTabbed() const override;
   bool IsTypePopup() const override;
-  bool IsTabPinned(const SyncedTabDelegate* tab) const override;
-  SyncedTabDelegate* GetTabAt(int index) const override;
+  bool IsTabPinned(const sync_sessions::SyncedTabDelegate* tab) const override;
+  sync_sessions::SyncedTabDelegate* GetTabAt(int index) const override;
   SessionID::id_type GetTabIdAt(int index) const override;
   bool IsSessionRestoreInProgress() const override;
   bool ShouldSync() const override;
 
  private:
   TabModel* tab_model_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncedWindowDelegateAndroid);
 };
 
-} // namespace browser_sync
+}  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNCED_WINDOW_DELEGATE_ANDROID_H_