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

chrome/common/nacl_host_messages.h

Index: chrome/common/nacl_host_messages.h
diff --git a/chrome/common/nacl_host_messages.h b/chrome/common/nacl_host_messages.h
index 13d1f460e735decdfbf15d6cacaa6ff7726786a2..cb13a6207c7306eda6b5b5ba29939425e9982e5e 100644
--- a/chrome/common/nacl_host_messages.h
+++ b/chrome/common/nacl_host_messages.h
@@ -54,6 +54,24 @@ IPC_SYNC_MESSAGE_CONTROL1_2(NaClHostMsg_LaunchNaCl,
                             std::string /* error_message */)
 
 // A renderer sends this to the browser process when it wants to
+// ensure that PNaCl is installed.
+IPC_MESSAGE_CONTROL1(NaClHostMsg_EnsurePnaclInstalled,
+                     int /* pp_instance */)
+
+// The browser replies to the renderer's request to ensure that
+// PNaCl is installed.
+IPC_MESSAGE_CONTROL2(NaClViewMsg_EnsurePnaclInstalledReply,
+                     int /* pp_instance */,
+                     bool /* success */)
+
+// The browser may send a progress event for the renderer's request
+// to ensure that PNaCl is installed.
+IPC_MESSAGE_CONTROL3(NaClViewMsg_EnsurePnaclInstalledProgress,
+                     int /* pp_instance */,
+                     int64_t /* current_progress */,
+                     int64_t /* total */)
+
+// A renderer sends this to the browser process when it wants to
 // open a file for from the Pnacl component directory.
 IPC_SYNC_MESSAGE_CONTROL1_1(NaClHostMsg_GetReadonlyPnaclFD,
                             std::string /* name of requested PNaCl file */,