Revert of Remove font cache code

chrome/utility/font_cache_handler_win.h

+// Copyright 2014 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 CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_
+#define CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_
+
+#include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/utility/utility_message_handler.h"
+
+namespace base {
+class TaskRunner;
+class Thread;
+}
+
+// Handles requests to build a static direct write font cache. Must be invoked
+// in a non-sandboxed utility process. We build static font cache in utility
+// process as it is time consuming as well as crash prone thing. We already
+// have fall back of loading fonts from system fonts directory in place, so even
+// if we fail to build static cache in utility process, chrome will still
+// continue to run as is.
+class FontCacheHandler : public UtilityMessageHandler {
+ public:
+  FontCacheHandler();
+  ~FontCacheHandler() override;
+
+  // IPC::Listener implementation
+  bool OnMessageReceived(const IPC::Message& message) override;
+
+ private:
+  void OnBuildFontCache(const base::FilePath& full_path);
+  void StartBuildingFontCache(const base::FilePath& full_path);
+  void Cleanup();
+
+  scoped_refptr<base::TaskRunner> utility_task_runner_;
+
+  // Thread that caching process runs on, while FontCacheHandler handles
+  // messages from the browser process.
+  scoped_ptr<base::Thread> cache_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(FontCacheHandler);
+};
+
+#endif  // CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_