Unify the three places that patch font loading for PDFium on Windows.

content/public/utility/utility_thread.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_UTILITY_UTILITY_THREAD_H_
 #define CONTENT_PUBLIC_UTILITY_UTILITY_THREAD_H_
 
 #include "base/basictypes.h"
-#include "content/common/content_export.h"
-#include "ipc/ipc_sender.h"
-
-#if defined(OS_WIN)
-#include <windows.h>
-#endif
+#include "content/public/child/child_thread.h"
 
 namespace content {
 
-class CONTENT_EXPORT UtilityThread : public IPC::Sender {
+class CONTENT_EXPORT UtilityThread : virtual public ChildThread {
  public:
   // Returns the one utility thread for this process.  Note that this can only
   // be accessed when running on the utility thread itself.
   static UtilityThread* Get();
 
   UtilityThread();
   ~UtilityThread() override;
 
   // Releases the process if we are not (or no longer) in batch mode.
   virtual void ReleaseProcessIfNeeded() = 0;
-
-#if defined(OS_WIN)
-  // Request that the given font be loaded by the browser so it's cached by the
-  // OS. Please see ChildProcessHost::PreCacheFont for details.
-  virtual void PreCacheFont(const LOGFONT& log_font) = 0;
-
-  // Release cached font.
-  virtual void ReleaseCachedFonts() = 0;
-#endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_UTILITY_UTILITY_THREAD_H_