Remove BackForwardClient, cleanup starting a history navigation

Source/web/BackForwardClientImpl.h

Index: Source/web/BackForwardClientImpl.h
diff --git a/Source/web/BackForwardClientImpl.h b/Source/web/BackForwardClientImpl.h
deleted file mode 100644
index ca0f07671bab598dab767ef341a0f790bed0a399..0000000000000000000000000000000000000000
--- a/Source/web/BackForwardClientImpl.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2009 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef BackForwardClientImpl_h
-#define BackForwardClientImpl_h
-
-#include "core/page/BackForwardClient.h"
-
-namespace blink {
-
-class WebViewImpl;
-
-class BackForwardClientImpl final : public BackForwardClient {
-public:
-    explicit BackForwardClientImpl(WebViewImpl*);
-    virtual ~BackForwardClientImpl();
-
-private:
-    // BackForwardList methods:
-    virtual int backListCount() override;
-    virtual int forwardListCount() override;
-    virtual int backForwardListCount() override;
-
-    WebViewImpl* m_webView;
-};
-
-} // namespace blink
-
-#endif