PlzNavigate: add support in several navigation controller unit tests

content/test/test_render_frame_host.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_TEST_TEST_RENDER_FRAME_HOST_H_
 #define CONTENT_TEST_TEST_RENDER_FRAME_HOST_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 77 matching lines @@
   void DidDisownOpener();
 
   // If set, navigations will appear to have cleared the history list in the
   // RenderFrame
   // (FrameHostMsg_DidCommitProvisionalLoad_Params::history_list_was_cleared).
   // False by default.
   void set_simulate_history_list_was_cleared(bool cleared) {
     simulate_history_list_was_cleared_ = cleared;
   }
 
+  // Advances the RenderFrameHost (and through it the RenderFrameHostManager) to
+  // a state where a new navigation can be committed by a renderer. Currently,
+  // this simulates a BeforeUnload ACK from the renderer.
+  // PlzNavigate: this simulates a BeforeUnload ACK from the renderer, and the
+  // interaction with the IO thread up until the response is ready to commit.
+  void PrepareForCommit(const GURL& url);
+
  private:
   TestRenderFrameHostCreationObserver child_creation_observer_;
 
   std::string contents_mime_type_;
 
   // See set_simulate_history_list_was_cleared() above.
   bool simulate_history_list_was_cleared_;
 
   DISALLOW_COPY_AND_ASSIGN(TestRenderFrameHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_RENDER_FRAME_HOST_H_