content: convert child process notifications to observer usage

content/browser/media/webrtc_internals.h

Index: content/browser/media/webrtc_internals.h
diff --git a/content/browser/media/webrtc_internals.h b/content/browser/media/webrtc_internals.h
index 402b6435aa06cdeabd3f6670efb94ca61987a30c..7baff52d8a6a9ecf0844a643431b683aa235607a 100644
--- a/content/browser/media/webrtc_internals.h
+++ b/content/browser/media/webrtc_internals.h
@@ -10,6 +10,7 @@
 #include "base/process.h"
 #include "base/values.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/browser_child_process_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
@@ -20,7 +21,8 @@ class WebRTCInternalsUIObserver;
 // It collects peer connection infomation from the renderers,
 // forwards the data to WebRTCInternalsUIObserver and
 // sends data collecting commands to the renderers.
-class CONTENT_EXPORT WebRTCInternals : public NotificationObserver{
+class CONTENT_EXPORT WebRTCInternals : public BrowserChildProcessObserver,
+                                       public NotificationObserver{
  public:
   static WebRTCInternals* GetInstance();
 
@@ -71,11 +73,18 @@ class CONTENT_EXPORT WebRTCInternals : public NotificationObserver{
 
   void SendUpdate(const std::string& command, base::Value* value);
 
+  // BrowserChildProcessObserver implementation.
+  virtual void BrowserChildProcessCrashed(
+      const ChildProcessData& data) OVERRIDE;
+
   // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
+  // Called when a renderer exits (including crashes).
+  void OnRendererExit(int render_process_id);
+
   ObserverList<WebRTCInternalsUIObserver> observers_;
 
   // |peer_connection_data_| is a list containing all the PeerConnection