Split off CPDF_Document into its own .cpp/.h files.

core/src/fpdfapi/fpdf_render/fpdf_render_cache.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/src/fpdfapi/fpdf_render/render_int.h"
 
+#include "core/include/fpdfapi/cpdf_document.h"
 #include "core/include/fpdfapi/fpdf_pageobj.h"
 #include "core/include/fpdfapi/fpdf_render.h"
 #include "core/include/fxge/fx_ge.h"
 #include "core/src/fpdfapi/fpdf_page/pageint.h"
 
 struct CACHEINFO {
   FX_DWORD time;
   CPDF_Stream* pStream;
 };
 
@@ skipping 305 matching lines @@
     m_pCurBitmap = NULL;
     return 0;
   }
   ContinueGetCachedBitmap();
   return 0;
 }
 void CPDF_ImageCacheEntry::CalcSize() {
   m_dwCacheSize = FPDF_ImageCache_EstimateImageSize(m_pCachedBitmap) +
                   FPDF_ImageCache_EstimateImageSize(m_pCachedMask);
 }
-void CPDF_Document::ClearRenderFont() {
-  if (m_pDocRender) {
-    CFX_FontCache* pCache = m_pDocRender->GetFontCache();
-    if (pCache) {
-      pCache->FreeCache(FALSE);
-    }
-  }
-}