Make pnacl install on demand when it is not already installed.

chrome/browser/nacl_host/pnacl_file_host.cc

Index: chrome/browser/nacl_host/pnacl_file_host.cc
diff --git a/chrome/browser/nacl_host/pnacl_file_host.cc b/chrome/browser/nacl_host/pnacl_file_host.cc
index 966fc7f9633e203af56ede0dbc846ef77366f5fc..0d03f8ee67a2c597606706ebfdbcc0c5e5400fd3 100644
--- a/chrome/browser/nacl_host/pnacl_file_host.cc
+++ b/chrome/browser/nacl_host/pnacl_file_host.cc
@@ -4,13 +4,18 @@
 
 #include "chrome/browser/nacl_host/pnacl_file_host.h"
 
+#include <iostream>
+
 #include "base/bind.h"
+#include "base/callback.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
 #include "base/platform_file.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
 #include "chrome/browser/renderer_host/chrome_render_message_filter.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/render_messages.h"
@@ -49,13 +54,59 @@ bool PnaclDoOpenFile(const base::FilePath& file_to_open,
   return true;
 }
 
-void DoOpenPnaclFile(
-    ChromeRenderMessageFilter* chrome_render_message_filter,
-    const std::string& filename,
-    IPC::Message* reply_msg) {
+void DoOpenPnaclFile(ChromeRenderMessageFilter* chrome_render_message_filter,
+                     const std::string& filename,
+                     IPC::Message* reply_msg);
+
+void PnaclCheckDone(ChromeRenderMessageFilter* chrome_render_message_filter,
+                    const std::string& filename,
+                    IPC::Message* reply_msg,
+                    bool success) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!success) {
+    NotifyRendererOfError(chrome_render_message_filter, reply_msg);
+  } else {
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        base::Bind(&DoOpenPnaclFile,
+                   make_scoped_refptr(chrome_render_message_filter),
+                   filename,
+                   reply_msg));
+  }
+}
+
+void TryInstallPnacl(ChromeRenderMessageFilter* chrome_render_message_filter,
+                     const std::string& filename,
+                     IPC::Message* reply_msg) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  ComponentUpdateService* cus = g_browser_process->component_updater();
+  CheckUpdatesForPnacl(cus,
+                       base::Bind(&PnaclCheckDone,
+                                  make_scoped_refptr(
+                                      chrome_render_message_filter),
+                                  filename,
+                                  reply_msg));
+}
+
+void DoOpenPnaclFile(ChromeRenderMessageFilter* chrome_render_message_filter,
+                     const std::string& filename,
+                     IPC::Message* reply_msg) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  base::FilePath full_filepath;
 
+  // PNaCl must be installed.
+  base::FilePath pnacl_dir;
+  if (!PathService::Get(chrome::DIR_PNACL_COMPONENT, &pnacl_dir) ||
+      !file_util::PathExists(pnacl_dir)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&TryInstallPnacl,
+                   make_scoped_refptr(chrome_render_message_filter),
+                   filename,
+                   reply_msg));
+    return;
+  }
+
+  FilePath full_filepath;
   // Do some validation.
   if (!pnacl_file_host::PnaclCanOpenFile(filename, &full_filepath)) {
     NotifyRendererOfError(chrome_render_message_filter, reply_msg);