Don't use LCD antialiasing if Fontconfig doesn't support hinting

core/fxge/ge/fx_ge_fontmap.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 <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 436 matching lines @@
     }
   }
   m_RefCount--;
   if (m_RefCount) {
     return m_RefCount;
   }
   delete this;
   return 0;
 }
 
 CFX_FontMgr::CFX_FontMgr() : m_FTLibrary(nullptr) {

[Lei Zhang, 2016/05/17 18:30:54]

Can you initialize |m_FTLibrarySupportsHinting| to false here anyway?

[Tom (Use chromium acct), 2016/05/17 19:06:37]

Done.

   m_pBuiltinMapper.reset(new CFX_FontMapper(this));
 }
 
 CFX_FontMgr::~CFX_FontMgr() {
   for (const auto& pair : m_FaceMap)
     delete pair.second;
 
   // |m_pBuiltinMapper| references |m_FTLibrary|, so it has to be destroyed
   // first.
   m_pBuiltinMapper.reset();
   FXFT_Done_FreeType(m_FTLibrary);
 }
 
 void CFX_FontMgr::InitFTLibrary() {
   if (m_FTLibrary)
     return;
   FXFT_Init_FreeType(&m_FTLibrary);
+  m_FTLibrarySupportsHinting =
+      FXFT_Library_SetLcdFilter(m_FTLibrary, FT_LCD_FILTER_DEFAULT) !=
+      FT_Err_Unimplemented_Feature;
 }
 
 void CFX_FontMgr::SetSystemFontInfo(IFX_SystemFontInfo* pFontInfo) {
   m_pBuiltinMapper->SetSystemFontInfo(pFontInfo);
 }
 
 FXFT_Face CFX_FontMgr::FindSubstFont(const CFX_ByteString& face_name,
                                      FX_BOOL bTrueType,
                                      uint32_t flags,
                                      int weight,
@@ skipping 156 matching lines @@
   }
   index -= FX_ArraySize(g_FoxitFonts);
   if (index < FX_ArraySize(g_MMFonts)) {
     *pFontData = g_MMFonts[index].m_pFontData;
     *size = g_MMFonts[index].m_dwSize;
     return true;
   }
   return false;
 }
 
+bool CFX_FontMgr::FTLibrarySupportsHinting() const {
+  if (!m_FTLibrary)

[Lei Zhang, 2016/05/17 18:30:54]

And don't worry about this.

[Tom (Use chromium acct), 2016/05/17 19:06:37]

Done.

+    return false;
+  return m_FTLibrarySupportsHinting;
+}
+
 CFX_FontMapper::CFX_FontMapper(CFX_FontMgr* mgr)
     : m_bListLoaded(FALSE),
       m_pFontInfo(nullptr),
       m_pFontMgr(mgr) {
   m_MMFaces[0] = nullptr;
   m_MMFaces[1] = nullptr;
   FXSYS_memset(m_FoxitFaces, 0, sizeof(m_FoxitFaces));
 }
 CFX_FontMapper::~CFX_FontMapper() {
   for (size_t i = 0; i < FX_ArraySize(m_FoxitFaces); ++i) {
@@ skipping 986 matching lines @@
 int PDF_GetStandardFontName(CFX_ByteString* name) {
   AltFontName* found = static_cast<AltFontName*>(
       FXSYS_bsearch(name->c_str(), g_AltFontNames, FX_ArraySize(g_AltFontNames),
                     sizeof(AltFontName), CompareString));
   if (!found)
     return -1;
 
   *name = g_Base14FontNames[found->m_Index];
   return found->m_Index;
 }