Move content::MakeSharedMemorySegmentViaIPC into its own file

content/common/child_process_sandbox_support_impl_linux.h

 // Copyright (c) 2011 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.
 
 #ifndef CONTENT_COMMON_CHILD_PROCESS_SANDBOX_SUPPORT_IMPL_LINUX_H_
 #define CONTENT_COMMON_CHILD_PROCESS_SANDBOX_SUPPORT_IMPL_LINUX_H_
 #pragma once
 
+#include "base/global_descriptors_posix.h"
+#include "content/common/chrome_descriptors.h"
 #include "content/public/common/child_process_sandbox_support_linux.h"
 
 namespace WebKit {
 struct WebFontFamily;
 struct WebFontRenderStyle;
 }
 
 namespace content {
 
 // Return a font family which provides glyphs for the Unicode code points
 // specified by |utf16|
 //   utf16: a native-endian UTF16 string
 //   num_utf16: the number of 16-bit words in |utf16|
 //   preferred_locale: preferred locale identifier for the |utf16|
 //
 // Returns: a font family instance.
 // The instance has an empty font name if the request could not be satisfied.
 void GetFontFamilyForCharacters(const uint16_t* utf16,
                                 size_t num_utf16,
                                 const char* preferred_locale,
                                 WebKit::WebFontFamily* family);
 
 void GetRenderStyleForStrike(const char* family, int sizeAndStyle,
                              WebKit::WebFontRenderStyle* out);
 
+inline int GetSandboxFD() {
+  return kSandboxIPCChannel + base::GlobalDescriptors::kBaseDescriptor;
+}
+
 };  // namespace content
 
 #endif  // CONTENT_COMMON_CHILD_PROCESS_SANDBOX_SUPPORT_IMPL_LINUX_H_