Introduce RenderProcessHostObserver, use it in its first client.

content/public/browser/render_process_host.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_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 
 #include "base/basictypes.h"
 #include "base/id_map.h"
 #include "base/process/kill.h"
 #include "base/process/process_handle.h"
 #include "base/supports_user_data.h"
 #include "content/common/content_export.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_sender.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/surface/transport_dib.h"
 
 class GURL;
 struct ViewMsg_SwapOut_Params;
 
 namespace base {
 class TimeDelta;
 }
 
 namespace content {
 class BrowserContext;
 class BrowserMessageFilter;
+class RenderProcessHostObserver;
 class RenderWidgetHost;
 class StoragePartition;
 
 typedef base::Thread* (*RendererMainThreadFactoryFunction)(
     const std::string& id);
 
 // Interface that represents the browser side of the browser <-> renderer
 // communication channel. There will generally be one RenderProcessHost per
 // renderer process.
 class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
                                          public IPC::Listener,
                                          public base::SupportsUserData {
  public:
   typedef IDMap<RenderProcessHost>::iterator iterator;
 
   // Details for RENDERER_PROCESS_CLOSED notifications.
   struct RendererClosedDetails {
     RendererClosedDetails(base::ProcessHandle handle,
                           base::TerminationStatus status,
                           int exit_code) {
       this->handle = handle;
       this->status = status;
       this->exit_code = exit_code;
     }
     base::ProcessHandle handle;
     base::TerminationStatus status;
     int exit_code;
   };
 
+  // General functions ---------------------------------------------------------
+
   virtual ~RenderProcessHost() {}
 
   // Initialize the new renderer process, returning true on success. This must
   // be called once before the object can be used, but can be called after
   // that with no effect. Therefore, if the caller isn't sure about whether
   // the process has been created, it should just call Init().
   virtual bool Init() = 0;
 
   // Gets the next available routing id.
   virtual int GetNextRoutingID() = 0;
 
   // These methods add or remove listener for a specific message routing ID.
   // Used for refcounting, each holder of this object must AddRoute and
   // RemoveRoute. This object should be allocated on the heap; when no
   // listeners own it any more, it will delete itself.
   virtual void AddRoute(int32 routing_id, IPC::Listener* listener) = 0;
   virtual void RemoveRoute(int32 routing_id) = 0;
 
+  // Add and remove observers for lifecycle events. The order in which
+  // notifications are sent to observers is undefined. Observers must be sure to
+  // remove the observer before they go away.
+  virtual void AddObserver(RenderProcessHostObserver* observer) = 0;
+  virtual void RemoveObserver(RenderProcessHostObserver* observer) = 0;
+  virtual bool HasObserver(RenderProcessHostObserver* observer) = 0;
+
   // Called to wait for the next UpdateRect message for the specified render
   // widget.  Returns true if successful, and the msg out-param will contain a
   // copy of the received UpdateRect message.
   virtual bool WaitForBackingStoreMsg(int render_widget_id,
                                       const base::TimeDelta& max_delay,
                                       IPC::Message* msg) = 0;
 
   // Called when a received message cannot be decoded.
   virtual void ReceivedBadMessage() = 0;
 
@@ skipping 169 matching lines @@
   // module.
   static size_t GetMaxRendererProcessCount();
 
   static void RegisterRendererMainThreadFactory(
       RendererMainThreadFactoryFunction create);
 };
 
 }  // namespace content.
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_