When launching PNaCl helper nexes, explicitly disable IRT loading.

chrome/browser/nacl_host/nacl_process_host.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/nacl_host/nacl_process_host.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 126 matching lines @@
 }
 
 bool NaClProcessHost::PluginListener::OnMessageReceived(
     const IPC::Message& msg) {
   return host_->OnUntrustedMessageForwarded(msg);
 }
 
 NaClProcessHost::NaClProcessHost(const GURL& manifest_url,
                                  int render_view_id,
                                  uint32 permission_bits,
-                                 bool off_the_record)
+                                 bool off_the_record,
+                                 bool uses_irt)
     : manifest_url_(manifest_url),
       permissions_(GetNaClPermissions(permission_bits)),
 #if defined(OS_WIN)
       process_launched_by_broker_(false),
 #elif defined(OS_LINUX)
       wait_for_nacl_gdb_(false),
 #endif
       reply_msg_(NULL),
 #if defined(OS_WIN)
       debug_exception_handler_requested_(false),
 #endif
       internal_(new NaClInternal()),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)),
       enable_exception_handling_(false),
       enable_debug_stub_(false),
       off_the_record_(off_the_record),
       enable_ipc_proxy_(false),
+      uses_irt_(uses_irt),
       ALLOW_THIS_IN_INITIALIZER_LIST(ipc_plugin_listener_(this)),
       render_view_id_(render_view_id) {
   process_.reset(content::BrowserChildProcessHost::Create(
       content::PROCESS_TYPE_NACL_LOADER, this));
 
   // Set the display name so the user knows what plugin the process is running.
   // We aren't on the UI thread so getting the pref locale for language
   // formatting isn't possible, so IDN will be lost, but this is probably OK
   // for this use case.
   process_->SetName(net::FormatUrl(manifest_url_, std::string()));
@@ skipping 530 matching lines @@
   NaClBrowser* nacl_browser = NaClBrowser::GetInstance();
 
   nacl::NaClStartParams params;
   params.validation_cache_enabled = nacl_browser->ValidationCacheIsEnabled();
   params.validation_cache_key = nacl_browser->GetValidationCacheKey();
   params.version = chrome::VersionInfo().CreateVersionString();
   params.enable_exception_handling = enable_exception_handling_;
   params.enable_debug_stub = enable_debug_stub_ &&
       NaClBrowser::GetInstance()->URLMatchesDebugPatterns(manifest_url_);
   params.enable_ipc_proxy = enable_ipc_proxy_;
-
-  base::PlatformFile irt_file = nacl_browser->IrtFile();
-  CHECK_NE(irt_file, base::kInvalidPlatformFileValue);
+  params.uses_irt = uses_irt_;
 
   const ChildProcessData& data = process_->GetData();
   for (size_t i = 0; i < internal_->sockets_for_sel_ldr.size(); i++) {
     if (!ShareHandleToSelLdr(data.handle,
                              internal_->sockets_for_sel_ldr[i], true,
                              &params.handles)) {
       return false;
     }
   }
 
-  // Send over the IRT file handle.  We don't close our own copy!
-  if (!ShareHandleToSelLdr(data.handle, irt_file, false, &params.handles))
-    return false;
+  if (params.uses_irt) {
+    // Send over the IRT file handle.  We don't close our own copy!

[Mark Seaborn, 2013/01/04 17:40:54]

I think this comment should stay next to the ShareHandleToSelLdr() call.  It's
commenting on the 'false' arg.

[jvoung (off chromium), 2013/01/04 17:59:27]

Done.

+    base::PlatformFile irt_file = nacl_browser->IrtFile();
+    CHECK_NE(irt_file, base::kInvalidPlatformFileValue);
+
+    if (!ShareHandleToSelLdr(data.handle, irt_file, false, &params.handles))
+      return false;
+  }
 
 #if defined(OS_MACOSX)
   // For dynamic loading support, NaCl requires a file descriptor that
   // was created in /tmp, since those created with shm_open() are not
   // mappable with PROT_EXEC.  Rather than requiring an extra IPC
   // round trip out of the sandbox, we create an FD here.
   base::SharedMemory memory_buffer;
   base::SharedMemoryCreateOptions options;
   options.size = 1;
   options.executable = true;
@@ skipping 188 matching lines @@
   } else {
     NaClStartDebugExceptionHandlerThread(
         process_handle.Take(), info,
         base::MessageLoopProxy::current(),
         base::Bind(&NaClProcessHost::OnDebugExceptionHandlerLaunchedByBroker,
                    weak_factory_.GetWeakPtr()));
     return true;
   }
 }
 #endif