Switch RenderFrameHostManager to use RenderProcessHostObserver, remove NOTIFICATION_RENDERER_PROCES…

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index e6df625995260a1880ca0af522c5ceaff11abee8..e6329d7c4994c94aa284ab530b1a30eda76d00da 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -2220,10 +2220,8 @@ void RenderProcessHostImpl::OnShutdownRequest() {
 
   // Notify any contents that might have swapped out renderers from this
   // process. They should not attempt to swap them back in.
-  NotificationService::current()->Notify(
-      NOTIFICATION_RENDERER_PROCESS_CLOSING,
-      Source<RenderProcessHost>(this),
-      NotificationService::NoDetails());
+  FOR_EACH_OBSERVER(RenderProcessHostObserver, observers_,
+                    RenderProcessWillExit(this));
 
   mojo_application_host_->WillDestroySoon();