content: convert child process notifications to observer usage

content/browser/plugin_process_host.cc

Index: content/browser/plugin_process_host.cc
diff --git a/content/browser/plugin_process_host.cc b/content/browser/plugin_process_host.cc
index d63aca94c94db47819fee48b22c77a4c51ac005d..97abec3499cddf69a72cb160af2af3e5a3b29049 100644
--- a/content/browser/plugin_process_host.cc
+++ b/content/browser/plugin_process_host.cc
@@ -28,6 +28,7 @@
 #include "content/common/child_process_host_impl.h"
 #include "content/common/plugin_messages.h"
 #include "content/common/resource_messages.h"
+#include "content/public/browser/browser_child_process_observer.h"

[jam, 2013/02/19 18:07:09]

nit: not needed?

[Paweł Hajdan Jr., 2013/02/20 12:11:42]

Done.

 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/notification_types.h"
@@ -342,7 +343,10 @@ void PluginProcessHost::CancelPendingRequestsForResourceContext(
 }
 
 void PluginProcessHost::OpenChannelToPlugin(Client* client) {
-  process_->Notify(NOTIFICATION_CHILD_INSTANCE_CREATED);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&BrowserChildProcessHostImpl::NotifyProcessInstanceCreated,
+                 process_->GetData()));
   client->SetPluginInfo(info_);
   if (process_->GetHost()->IsChannelOpening()) {
     // The channel is already in the process of being opened.  Put