Revert of Remove font cache code

content/child/font_warmup_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 CONTENT_CHILD_FONT_WARMUP_WIN_H_
 #define CONTENT_CHILD_FONT_WARMUP_WIN_H_
 
 #include <stddef.h>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "content/common/content_export.h"
 
 class SkFontMgr;
 class SkTypeface;
 
 namespace content {
 
+// Make necessary calls to cache the data for a given font, used before
+// sandbox lockdown.
+CONTENT_EXPORT void DoPreSandboxWarmupForTypeface(SkTypeface* typeface);
+
+// Get the shared font manager used during pre-sandbox warmup for DirectWrite
+// fonts.
+CONTENT_EXPORT SkFontMgr* GetPreSandboxWarmupFontMgr();
+
 class GdiFontPatchData {
  public:
   virtual ~GdiFontPatchData() {}
 
  protected:
   GdiFontPatchData() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GdiFontPatchData);
 };
 
 // Hook a module's imported GDI font functions to reimplement font enumeration
 // and font data retrieval for DLLs which can't be easily modified.
 CONTENT_EXPORT GdiFontPatchData* PatchGdiFontEnumeration(
     const base::FilePath& path);
 
 // Testing method to get the number of in-flight emulated GDI handles.
 CONTENT_EXPORT size_t GetEmulatedGdiHandleCountForTesting();
 
 // Testing method to reset the table of emulated GDI handles.
 CONTENT_EXPORT void ResetEmulatedGdiHandlesForTesting();
 
 // Sets the pre-sandbox warmup font manager directly. This should only be used
 // for testing the implementation.
 CONTENT_EXPORT void SetPreSandboxWarmupFontMgrForTesting(SkFontMgr* fontmgr);
 
+// Warmup the direct write font manager for content processes.
+CONTENT_EXPORT void WarmupDirectWrite();
+
 // Directwrite connects to the font cache service to retrieve information about
 // fonts installed on the system etc. This works well outside the sandbox and
 // within the sandbox as long as the lpc connection maintained by the current
 // process with the font cache service remains valid. It appears that there
 // are cases when this connection is dropped after which directwrite is unable
 // to connect to the font cache service which causes problems with characters
 // disappearing.
 // Directwrite has fallback code to enumerate fonts if it is unable to connect
 // to the font cache service. We need to intercept the following APIs to
 // ensure that it does not connect to the font cache service.
 // NtALpcConnectPort
 // OpenSCManagerW
 // OpenServiceW
 // StartServiceW
 // CloseServiceHandle.
 // These are all IAT patched.
 CONTENT_EXPORT void PatchServiceManagerCalls();
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_FONT_WARMUP_WIN_H_