Fix fonts not loading in PDFs that don't embed them.

chrome/child/pdf_child_init.cc

 // Copyright 2015 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.
 
 #include "chrome/child/pdf_child_init.h"
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "chrome/common/chrome_paths.h"
@@ skipping 32 matching lines @@
                               DWORD offset,
                               LPVOID buffer,
                               DWORD length) {
   int rv = g_original_get_font_data(hdc, table, offset, buffer, length);
   if (rv == GDI_ERROR && hdc) {
     HFONT font = static_cast<HFONT>(GetCurrentObject(hdc, OBJ_FONT));
 
     LOGFONT logfont;
     if (GetObject(font, sizeof(LOGFONT), &logfont)) {
       std::vector<char> font_data;
-      content::ChildThread::Get()->PreCacheFont(logfont);
+      if (content::ChildThread::Get())
+        content::ChildThread::Get()->PreCacheFont(logfont);
       rv = g_original_get_font_data(hdc, table, offset, buffer, length);
-      content::ChildThread::Get()->ReleaseCachedFonts();
+      if (content::ChildThread::Get())
+        content::ChildThread::Get()->ReleaseCachedFonts();
     }
   }
   return rv;
 }
 #endif  // OS_WIN
 
 }  // namespace
 
 void InitializePDF() {
 #if defined(OS_WIN)
@@ skipping 11 matching lines @@
   g_iat_patch_createdca.Patch(current_module_name, "gdi32.dll", "CreateDCA",
                               CreateDCAPatch);
   g_iat_patch_get_font_data.Patch(current_module_name, "gdi32.dll",
                                   "GetFontData", GetFontDataPatch);
   g_original_get_font_data = reinterpret_cast<GetFontDataPtr>(
       g_iat_patch_get_font_data.original_function());
 #endif  // OS_WIN
 }
 
 }  // namespace chrome