Add RoutingIDIssuer to ensure the correctness of ID to be routed.

content/browser/renderer_host/render_widget_helper.h

 // Copyright (c) 2012 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_RENDERER_HOST_RENDER_WIDGET_HELPER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_
 
 #include <map>
 
-#include "base/atomic_sequence_num.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/process/process.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/common/window_container_type.h"
 #include "third_party/WebKit/public/web/WebPopupType.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/surface/transport_dib.h"
 
 namespace IPC {
 class Message;
 }
 
 namespace base {
 class TimeDelta;
 }
 
 struct ViewHostMsg_CreateWindow_Params;
 struct ViewMsg_SwapOut_Params;
 
 namespace content {
 class GpuProcessHost;
 class ResourceDispatcherHostImpl;
+class RoutingIDIssuer;
 class SessionStorageNamespace;
 
 // Instantiated per RenderProcessHost to provide various optimizations on
 // behalf of a RenderWidgetHost.  This class bridges between the IO thread
 // where the RenderProcessHost's MessageFilter lives and the UI thread where
 // the RenderWidgetHost lives.
 //
 //
 // OPTIMIZED TAB SWITCHING
 //
@@ skipping 27 matching lines @@
     : public base::RefCountedThreadSafe<RenderWidgetHelper,
                                         BrowserThread::DeleteOnIOThread> {
  public:
   RenderWidgetHelper();
 
   void Init(int render_process_id,
             ResourceDispatcherHostImpl* resource_dispatcher_host);
 
   // Gets the next available routing id.  This is thread safe.
   int GetNextRoutingID();
+  // Probablistically verify if he ID is issued by this helper.

[nasko, 2014/10/13 21:04:00]

nit: s/if he/if the/

[Hajime Morrita, 2014/10/13 22:23:54]

Done.

+  // Thread safe.
+  int IsRoutingIDProbablyValid(int routing_id) const;

[nasko, 2014/10/13 21:04:00]

Why return int, when the expected output value is boolean?

[Hajime Morrita, 2014/10/13 22:23:54]

Oops. should've returned a bool.

 
   // IO THREAD ONLY -----------------------------------------------------------
 
   // Lookup the RenderWidgetHelper from the render_process_host_id. Returns NULL
   // if not found. NOTE: The raw pointer is for temporary use only. To retain,
   // store in a scoped_refptr.
   static RenderWidgetHelper* FromProcessHostID(int render_process_host_id);
 
   // UI THREAD ONLY -----------------------------------------------------------
 
@@ skipping 75 matching lines @@
   void ClearAllocatedDIBs();
 
   // On POSIX we keep file descriptors to all the allocated DIBs around until
   // the renderer frees them.
   base::Lock allocated_dibs_lock_;
   std::map<TransportDIB::Id, int> allocated_dibs_;
 #endif
 
   int render_process_id_;
 
-  // The next routing id to use.
-  base::AtomicSequenceNumber next_routing_id_;
+  scoped_ptr<RoutingIDIssuer> routing_id_issuer_;
 
   ResourceDispatcherHostImpl* resource_dispatcher_host_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHelper);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_