PNaCl on-demand installs: Make a separate async IPC to check if PNaCl is installed

chrome/browser/nacl_host/nacl_host_message_filter.h

Index: chrome/browser/nacl_host/nacl_host_message_filter.h
diff --git a/chrome/browser/nacl_host/nacl_host_message_filter.h b/chrome/browser/nacl_host/nacl_host_message_filter.h
index 66af82de625f7c31a19c1afd281a843eb3ef4048..dccdf083370d8760140348e0dd8a4e1528d62a1b 100644
--- a/chrome/browser/nacl_host/nacl_host_message_filter.h
+++ b/chrome/browser/nacl_host/nacl_host_message_filter.h
@@ -16,6 +16,7 @@ class GURL;
 namespace nacl {
 struct NaClLaunchParams;
 struct PnaclCacheInfo;
+struct PnaclInstallProgress;
 }
 
 namespace net {
@@ -51,6 +52,7 @@ class NaClHostMessageFilter : public content::BrowserMessageFilter {
 #if !defined(DISABLE_NACL)
   void OnLaunchNaCl(const nacl::NaClLaunchParams& launch_params,
                     IPC::Message* reply_msg);
+  void OnEnsurePnaclInstalled(int instance);
   void OnGetReadonlyPnaclFd(const std::string& filename,
                             IPC::Message* reply_msg);
   void OnNaClCreateTemporaryFile(IPC::Message* reply_msg);
@@ -63,6 +65,10 @@ class NaClHostMessageFilter : public content::BrowserMessageFilter {
                             const GURL& file_url,
                             IPC::Message* reply_msg);
 
+  void ReplyEnsurePnaclInstalled(int instance, bool success);
+  void SendProgressEnsurePnaclInstalled(
+      int instance,
+      const nacl::PnaclInstallProgress& progress);
   void SyncReturnTemporaryFile(IPC::Message* reply_msg,
                                IPC::PlatformFileForTransit fd);
   void AsyncReturnTemporaryFile(int pp_instance,