Add a switch for using PNaCl Subzero and use it for -O0 translation.

components/nacl/common/nacl_switches.cc

 // Copyright 2013 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 "components/nacl/common/nacl_switches.h"
 
 namespace switches {
 
 // Disables crash throttling for Portable Native Client.
 const char kDisablePnaclCrashThrottling[]   = "disable-pnacl-crash-throttling";
 
 // Enables debugging via RSP over a socket.
 const char kEnableNaClDebug[]               = "enable-nacl-debug";
 
 // Enables Mojo support for Native Client plugins.
 const char kEnableNaClMojo[]                = "enable-nacl-mojo";
 
 // Enables Non-SFI mode, in which programs can be run without NaCl's SFI
 // sandbox.
 const char kEnableNaClNonSfiMode[]          = "enable-nacl-nonsfi-mode";
 
+// Enable use of the Subzero as the PNaCl translator instead of LLC.
+const char kEnablePNaClSubzero[] = "enable-pnacl-subzero";
+
 // Value for --type that causes the process to run as a NativeClient broker
 // (used for launching NaCl loader processes on 64-bit Windows).
 const char kNaClBrokerProcess[]             = "nacl-broker";
 
 // Disable sandbox even for non SFI mode. This is particularly unsafe
 // as non SFI NaCl heavily relies on the seccomp sandbox.
 const char kNaClDangerousNoSandboxNonSfi[]  =
     "nacl-dangerous-no-sandbox-nonsfi";
 
 // Uses NaCl manifest URL to choose whether NaCl program will be debugged by
@@ skipping 21 matching lines @@
 const char kNaClLoaderProcess[]             = "nacl-loader";
 
 // Use nacl_helper_nonsfi executable (the new, newlib-based version of the
 // Non-SFI runtime) to run Non-SFI nexe, instead of nacl_helper executable
 // (which uses the older, glib-based runtime for Non-SFI mode).
 // TODO(hidehiko): Make this default and then remove this flag after
 // nacl_helper_nonsfi is supported.
 const char kUseNaClHelperNonSfi[]           = "use-nacl-helper-nonsfi";
 
 }  // namespace switches