Change the DidChangeView update to take a new ViewChanged resource.

chrome/browser/nacl_host/nacl_process_host.h

Index: chrome/browser/nacl_host/nacl_process_host.h
diff --git a/chrome/browser/nacl_host/nacl_process_host.h b/chrome/browser/nacl_host/nacl_process_host.h
index 265e34fc26c876ad21f702a2ea6c887bf1fd460b..6641c49e11e43b8b7676292505379ae9b5d2a8d2 100644
--- a/chrome/browser/nacl_host/nacl_process_host.h
+++ b/chrome/browser/nacl_host/nacl_process_host.h
@@ -31,7 +31,10 @@ class NaClProcessHost : public BrowserChildProcessHost {
   // Do any minimal work that must be done at browser startup.
   static void EarlyStartup();
 
-  // Initialize the new NaCl process, returning true on success.
+  // Initialize the new NaCl process, returning true on success. On success,
+  // the NaCl process host will assume responsibility for sending the reply
+  // message. On failure, the reply will not be sent and this is the caller's
+  // responsibility to avoid handling the renderer.

[dmichael (off chromium), 2011/12/20 19:01:34]

"avoid handling the renderer"? Is it supposed to say "hanging" or something?

   bool Launch(ChromeRenderMessageFilter* chrome_render_message_filter,
               int socket_count,
               IPC::Message* reply_msg);
@@ -62,7 +65,9 @@ class NaClProcessHost : public BrowserChildProcessHost {
   // this for sending the reply once the process has started.
   scoped_refptr<ChromeRenderMessageFilter> chrome_render_message_filter_;
 
-  // The reply message to send.
+  // The reply message to send. We must always send this message when the
+  // sub-process either succeeds or fails to unblock the renderer waiting for
+  // the reply. NULL when there is no reply to send.
   IPC::Message* reply_msg_;
 
   // Socket pairs for the NaCl process and renderer.