Remove nonsfi token workaround.

components/nacl/browser/nacl_file_host.cc

Index: components/nacl/browser/nacl_file_host.cc
diff --git a/components/nacl/browser/nacl_file_host.cc b/components/nacl/browser/nacl_file_host.cc
index 17e5bc5ea4208b7df545403d7b6110361051c842..2410e11bd50099f10f6ef739d3f72c33852273a3 100644
--- a/components/nacl/browser/nacl_file_host.cc
+++ b/components/nacl/browser/nacl_file_host.cc
@@ -122,6 +122,7 @@ void DoOpenPnaclFile(
 void DoOpenNaClExecutableOnThreadPool(
     scoped_refptr<nacl::NaClHostMessageFilter> nacl_host_message_filter,
     const GURL& file_url,
+    bool enable_validation_caching,
     IPC::Message* reply_msg) {
   DCHECK(BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
 
@@ -138,16 +139,31 @@ void DoOpenNaClExecutableOnThreadPool(
   base::File file = nacl::OpenNaClReadExecImpl(file_path,
                                                true /* is_executable */);
   if (file.IsValid()) {
-    // This function is running on the blocking pool, but the path needs to be
-    // registered in a structure owned by the IO thread.
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(
-            &DoRegisterOpenedNaClExecutableFile,
-            nacl_host_message_filter,
-            Passed(file.Pass()), file_path, reply_msg,
-            static_cast<WriteFileInfoReply>(
-                NaClHostMsg_OpenNaClExecutable::WriteReplyParams)));
+    // Opening a NaCl executable works with or without validation caching.
+    // Validation caching requires that the file descriptor is registered now
+    // for later use, which will save time.
+    // When validation caching isn't used (e.g. Non-SFI mode), there is no
+    // reason to do that unnecessary registration.
+    if (enable_validation_caching) {
+      // This function is running on the blocking pool, but the path needs to be
+      // registered in a structure owned by the IO thread.
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE,
+          base::Bind(
+              &DoRegisterOpenedNaClExecutableFile,
+              nacl_host_message_filter,
+              Passed(file.Pass()), file_path, reply_msg,
+              static_cast<WriteFileInfoReply>(
+                  NaClHostMsg_OpenNaClExecutable::WriteReplyParams)));
+    } else {
+      IPC::PlatformFileForTransit file_desc =
+          IPC::TakeFileHandleForProcess(file.Pass(),
+                                        nacl_host_message_filter->PeerHandle());
+      uint64_t dummy_file_token = 0;
+      NaClHostMsg_OpenNaClExecutable::WriteReplyParams(
+          reply_msg, file_desc, dummy_file_token, dummy_file_token);
+      nacl_host_message_filter->Send(reply_msg);
+    }
   } else {
     NotifyRendererOfError(nacl_host_message_filter.get(), reply_msg);
     return;
@@ -211,6 +227,7 @@ void OpenNaClExecutable(
     scoped_refptr<nacl::NaClHostMessageFilter> nacl_host_message_filter,
     int render_view_id,
     const GURL& file_url,
+    bool enable_validation_caching,
     IPC::Message* reply_msg) {
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(
@@ -218,7 +235,10 @@ void OpenNaClExecutable(
         base::Bind(
             &OpenNaClExecutable,
             nacl_host_message_filter,
-            render_view_id, file_url, reply_msg));
+            render_view_id,
+            file_url,
+            enable_validation_caching,
+            reply_msg));
     return;
   }
 
@@ -247,7 +267,9 @@ void OpenNaClExecutable(
       base::Bind(
           &DoOpenNaClExecutableOnThreadPool,
           nacl_host_message_filter,
-          file_url, reply_msg))) {
+          file_url,
+          enable_validation_caching,
+          reply_msg))) {
     NotifyRendererOfError(nacl_host_message_filter.get(), reply_msg);
   }
 }