PlzNavigate: implement REUSE_COMMITTED_OR_PENDING_SITE for redirects

content/browser/frame_host/render_frame_host_manager.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_RENDER_FRAME_HOST_MANAGER_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_MANAGER_H_
 
 #include <stdint.h>
 
 #include <list>
@@ skipping 487 matching lines @@
 
   void OnSetHasReceivedUserGesture();
 
   // Sets up the necessary state for a new RenderViewHost.  If |proxy| is not
   // null, it creates a RenderFrameProxy in the target renderer process which is
   // used to route IPC messages when in swapped out state.  Returns early if the
   // RenderViewHost has already been initialized for another RenderFrameHost.
   bool InitRenderView(RenderViewHostImpl* render_view_host,
     RenderFrameProxyHost* proxy);
 
+  // Returns the SiteInstance that should be used to host the navigation handled
+  // by |navigation_request|.
+  // Note: the SiteInstance returned by this function may not have an
+  // initialized RenderProcessHost. It will only be initialized when
+  // GetProcess() is called on the SiteInstance. In particular, calling this
+  // function will never lead to a process being created for the navigation.
+  scoped_refptr<SiteInstance> GetSiteInstanceForNavigationRequest(
+      const NavigationRequest& navigation_request);
+
  private:
   friend class NavigatorTestWithBrowserSideNavigation;
   friend class RenderFrameHostManagerTest;
   friend class RenderFrameHostTester;
   friend class TestWebContents;
 
   enum class SiteInstanceRelation {
     // A SiteInstance in a different browsing instance from the current.
     UNRELATED,
     // A SiteInstance in the same browsing instance as the current.
@@ skipping 279 matching lines @@
   std::unique_ptr<RenderFrameHostImpl> speculative_render_frame_host_;
 
   base::WeakPtrFactory<RenderFrameHostManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_MANAGER_H_