Navigation transitions: Place transition page in same process as destination page.

content/browser/transition_request_manager.h

 // Copyright 2014 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_TRANSITION_REQUEST_MANAGER_H_
 #define CONTENT_BROWSER_TRANSITION_REQUEST_MANAGER_H_
 
+#include <map>
 #include <set>
+#include <string>
 #include <utility>
 
 #include "base/basictypes.h"
 #include "content/common/content_export.h"
 
 template <typename T>
 struct DefaultSingletonTraits;
 
+class GURL;
+
 namespace content {
 
 // TransitionRequestManager is used to handle bookkeeping for transition
 // requests and responses.
 //
 // TransitionRequestManager is a singleton and should only be accessed on the IO
 // thread.

[jam, 2014/07/14 23:14:21]

this comment would have to be updated per below

[shatch, 2014/07/21 17:47:11]

Done.

 //
 class TransitionRequestManager {
  public:
   // Returns the singleton instance.
   CONTENT_EXPORT static TransitionRequestManager* GetInstance();
 
+  // Accessed from IO thread only ----------------------------------------------
+
   // Returns whether the RenderFrameHost specified by the given IDs currently
   // has a pending transition request. If so, we will have to delay the
   // response until the embedder resumes the request.
   bool HasPendingTransitionRequest(int process_id, int render_frame_id);
 
   // Sets whether the RenderFrameHost specified by the given IDs currently has a
   // pending transition request.
   CONTENT_EXPORT void SetHasPendingTransitionRequest(int process_id,
                                                      int render_frame_id,
                                                      bool has_pending);
 
+  // Accessed from UI thread only ----------------------------------------------
+
+  // These functions are used to store the process ID for an outgoing
+  // navigation, so that the same renderer can be reused by the transition.
+  void AddPendingTransitionProcessID(const GURL& token, int process_id);
+  void ClearPendingTransitionProcessID(const GURL& token);
+  int GetPendingTransitionProcessIDByToken(const GURL& token);
+
+  // Creates a unique transition url that is used to identify which process
+  // to use during a transition.
+  GURL CreateTransitionURL();
+
  private:
   friend struct DefaultSingletonTraits<TransitionRequestManager>;
   typedef std::set<std::pair<int, int> > RenderFrameSet;
+  typedef std::map<std::string, int> ProcessIDMap;
 
   TransitionRequestManager();
   ~TransitionRequestManager();
 
   // Set of (render_process_host_id, render_frame_id) pairs of all
   // RenderFrameHosts that have pending transition requests. Used to pass
   // information to the CrossSiteResourceHandler without doing a round-trip
   // between IO->UI->IO threads.
   RenderFrameSet pending_transition_frames_;
 
+  // Map of transition urls to process ids for process sharing.
+  ProcessIDMap transition_process_ids_;
+
+  int transition_unique_ids_;
+
   DISALLOW_COPY_AND_ASSIGN(TransitionRequestManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TRANSITION_REQUEST_MANAGER_H_