Update the scale factor for font param before querying the default font.

chrome/browser/ui/libgtkui/gtk_ui.cc

 // Copyright (c) 2012 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/browser/ui/libgtkui/gtk_ui.h"
 
 #include <math.h>
 #include <pango/pango.h>
 #include <X11/Xcursor/Xcursor.h>
 
@@ skipping 28 matching lines @@
 #include "chrome/grit/theme_resources.h"
 #include "components/grit/components_scaled_resources.h"
 #include "printing/features/features.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/display/display.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/font_render_params.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_skia_source.h"
 #include "ui/gfx/skbitmap_operations.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/x/x11_types.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/controls/button/blue_button.h"
@@ skipping 882 matching lines @@
 
   if (theme)
     XcursorSetTheme(gfx::GetXDisplay(), theme);
   if (size)
     XcursorSetDefaultSize(gfx::GetXDisplay(), size);
 
   g_free(theme);
 }
 
 void GtkUi::UpdateDefaultFont() {
+  gfx::SetFontRenderParamsDeviceScaleFactor(device_scale_factor_);
+
   GtkWidget* fake_label = gtk_label_new(nullptr);
   g_object_ref_sink(fake_label);  // Remove the floating reference.
   PangoContext* pc = gtk_widget_get_pango_context(fake_label);
   const PangoFontDescription* desc = pango_context_get_font_description(pc);
 
   // Use gfx::FontRenderParams to select a family and determine the rendering
   // settings.
   gfx::FontRenderParamsQuery query;
   query.families =
       base::SplitString(pango_font_description_get_family(desc), ",",
@@ skipping 63 matching lines @@
 
 float GtkUi::GetDeviceScaleFactor() const {
   return device_scale_factor_;
 }
 
 }  // namespace libgtkui
 
 views::LinuxUI* BuildGtkUi() {
   return new libgtkui::GtkUi;
 }