Move navigation and frame tree classes to a new frame_host/ directory.

content/browser/frame_host/debug_urls.h

Index: content/browser/frame_host/debug_urls.h
diff --git a/content/browser/web_contents/debug_urls.h b/content/browser/frame_host/debug_urls.h
similarity index 74%
rename from content/browser/web_contents/debug_urls.h
rename to content/browser/frame_host/debug_urls.h
index 79da209c53a98643925d0c036ceefcf881b976c5..86e6520efefce36dbfad8add6f09e68040e11361 100644
--- a/content/browser/web_contents/debug_urls.h
+++ b/content/browser/frame_host/debug_urls.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_BROWSER_WEB_CONTENTS_DEBUG_URLS_H_
-#define CONTENT_BROWSER_WEB_CONTENTS_DEBUG_URLS_H_
+#ifndef CONTENT_BROWSER_FRAME_HOST_DEBUG_URLS_H_
+#define CONTENT_BROWSER_FRAME_HOST_DEBUG_URLS_H_
 
 #include "content/public/common/page_transition_types.h"
 
@@ -17,4 +17,4 @@ bool HandleDebugURL(const GURL& url, PageTransition transition);
 
 }  // namespace content
 
-#endif  // CONTENT_BROWSER_WEB_CONTENTS_DEBUG_URLS_H_
+#endif  // CONTENT_BROWSER_FRAME_HOST_DEBUG_URLS_H_