Add font substitution metric for Linux

pdf/pdfium/pdfium_page.cc

 // Copyright (c) 2010 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 "pdf/pdfium/pdfium_page.h"
 
 #include <math.h>
 #include <stddef.h>
 
 #include <algorithm>
@@ skipping 100 matching lines @@
     if (engine_->form()) {
       FORM_OnBeforeClosePage(page_, engine_->form());
     }
     FPDF_ClosePage(page_);
     page_ = nullptr;
   }
 }
 
 FPDF_PAGE PDFiumPage::GetPage() {
   ScopedUnsupportedFeature scoped_unsupported_feature(engine_);
+  ScopedSubstFont scoped_subst_font(engine_);
   if (!available_)
     return nullptr;
   if (!page_) {
     ScopedLoadCounter scoped_load(this);
     page_ = FPDF_LoadPage(engine_->doc(), index_);
     if (page_ && engine_->form()) {
       FORM_OnAfterLoadPage(page_, engine_->form());
     }
   }
   return page_;
 }
 
 FPDF_PAGE PDFiumPage::GetPrintPage() {
   ScopedUnsupportedFeature scoped_unsupported_feature(engine_);
+  ScopedSubstFont scoped_subst_font(engine_);
   if (!available_)
     return nullptr;
   if (!page_) {
     ScopedLoadCounter scoped_load(this);
     page_ = FPDF_LoadPage(engine_->doc(), index_);
   }
   return page_;
 }
 
 void PDFiumPage::ClosePrintPage() {
@@ skipping 371 matching lines @@
   page_->loading_count_--;
 }
 
 PDFiumPage::Link::Link() = default;
 
 PDFiumPage::Link::Link(const Link& that) = default;
 
 PDFiumPage::Link::~Link() = default;
 
 }  // namespace chrome_pdf