Support null language for fallbackFontForChar's IPC wrapper

content/common/child_process_sandbox_support_impl_linux.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 "content/common/child_process_sandbox_support_impl_linux.h"
 
 #include <sys/stat.h>
 
 #include "base/debug/trace_event.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 10 matching lines @@
 namespace content {
 
 void GetFallbackFontForCharacter(int32_t character,
                                  const char* preferred_locale,
                                  blink::WebFallbackFont* fallbackFont) {
   TRACE_EVENT0("sandbox_ipc", "GetFontFamilyForCharacter");
 
   Pickle request;
   request.WriteInt(LinuxSandbox::METHOD_GET_FALLBACK_FONT_FOR_CHAR);
   request.WriteInt(character);
-  request.WriteString(preferred_locale);
+  if (preferred_locale) {
+    request.WriteBool(true);
+    request.WriteString(preferred_locale);
+  } else
+    request.WriteBool(false);
 
   uint8_t buf[512];
   const ssize_t n = UnixDomainSocket::SendRecvMsg(GetSandboxFD(), buf,
                                                   sizeof(buf), NULL, request);
 
   std::string family_name;
   std::string filename;
   int fontconfigInterfaceId = 0;
   int ttcIndex = 0;
   bool isBold = false;
@@ skipping 150 matching lines @@
 }
 
 bool SendZygoteChildPing(int fd) {
   return UnixDomainSocket::SendMsg(fd,
                                    kZygoteChildPingMessage,
                                    sizeof(kZygoteChildPingMessage),
                                    std::vector<int>());
 }
 
 }  // namespace content