Move out DidStartProvisionalLoad from WebContentsImpl into Navigator.

content/browser/frame_host/navigator_delegate.h

+// Copyright 2013 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 CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_DELEGATE_H_
+#define CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_DELEGATE_H_
+
+class GURL;
+
+namespace content {
+
+class RenderFrameHost;
+
+// A delegate API used by Navigator to notify its embedder of navigation
+// related events.
+class NavigatorDelegate {
+
+ public:
+  virtual void DidStartProvisionalLoad(int64 frame_id,
+                                       int64 parent_frame_id,
+                                       bool is_main_frame,
+                                       const GURL& validated_url,
+                                       bool is_error_page,
+                                       bool is_iframe_srcdoc,
+                                       RenderFrameHost* render_frame_host) = 0;
+
+  virtual void ProvisionalChangeToMainFrameUrl(
+      const GURL& url,
+      RenderFrameHost* render_frame_host) = 0;
+
+  virtual void NotifyNavigationStateChanged(unsigned changed_flags) = 0;
+
+ private:
+};
+
+}  // namspace content
+
+#endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATOR_DELEGATE_H_