Unify the three places that patch font loading for PDFium on Windows.

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"
+#include "content/public/child/child_thread.h"
+
+#if defined(OS_WIN)
+#include "base/win/iat_patch_function.h"
+#endif
+
+namespace chrome {
+namespace {
+#if defined(OS_WIN)
+static base::win::IATPatchFunction g_iat_patch_createdca;
+HDC WINAPI CreateDCAPatch(LPCSTR driver_name,
+                          LPCSTR device_name,
+                          LPCSTR output,
+                          const void* init_data) {
+  DCHECK(std::string("DISPLAY") == std::string(driver_name));
+  DCHECK(!device_name);
+  DCHECK(!output);
+  DCHECK(!init_data);
+
+  // CreateDC fails behind the sandbox, but not CreateCompatibleDC.
+  return CreateCompatibleDC(NULL);
+}
+
+static base::win::IATPatchFunction g_iat_patch_get_font_data;
+DWORD WINAPI GetFontDataPatch(HDC hdc,
+                              DWORD table,
+                              DWORD offset,
+                              LPVOID buffer,
+                              DWORD length) {
+  int rv = GetFontData(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);
+      rv = GetFontData(hdc, table, offset, buffer, length);
+      content::ChildThread::Get()->ReleaseCachedFonts();
+    }
+  }
+  return rv;
+}
+#endif  // OS_WIN
+
+}  // namespace
+
+void InitializePDF() {
+#if defined(OS_WIN)
+  // Need to patch a few functions for font loading to work correctly. This can
+  // be removed once we switch PDF to use Skia.
+  base::FilePath pdf;
+  if (PathService::Get(chrome::FILE_PDF_PLUGIN, &pdf) &&
+      base::PathExists(pdf)) {
+    g_iat_patch_createdca.Patch(pdf.value().c_str(), "gdi32.dll", "CreateDCA",
+                                CreateDCAPatch);
+    g_iat_patch_get_font_data.Patch(pdf.value().c_str(), "gdi32.dll",
+                                    "GetFontData", GetFontDataPatch);
+  }
+#endif
+}
+
+}  // namespace chrome