Fix Pango font rendering with HiDPi displays on Linux.

chrome/browser/ui/libgtk2ui/gtk2_ui.h

 // Copyright (c) 2013 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.
 
 #ifndef CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_
 #define CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_
 
 #include <map>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/ui/libgtk2ui/gtk2_signal.h"
 #include "chrome/browser/ui/libgtk2ui/gtk2_signal_registrar.h"
 #include "chrome/browser/ui/libgtk2ui/libgtk2ui_export.h"
 #include "chrome/browser/ui/libgtk2ui/owned_widget_gtk2.h"
 #include "ui/events/linux/text_edit_key_bindings_delegate_auralinux.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/views/linux_ui/linux_ui.h"
 #include "ui/views/window/frame_buttons.h"
 
 typedef struct _GdkColor GdkColor;
 typedef struct _GtkBorder GtkBorder;
 typedef struct _GtkStyle GtkStyle;
 typedef struct _GtkWidget GtkWidget;
+typedef struct _PangoFontDescription PangoFontDescription;

[Daniel Erat, 2015/03/16 13:57:53]

you might want to rebase or merge your change against tip-of-tree -- i think
that this typedef has already been present for a few weeks.

[stapelberg, 2015/03/17 08:36:33]

Done.

 
 class SkBitmap;
 
 namespace gfx {
 class Image;
 }
 
 namespace libgtk2ui {
 class Gtk2Border;
 class Gtk2KeyBindingsHandler;
@@ skipping 26 matching lines @@
   // ui::LinuxInputMethodContextFactory:
   scoped_ptr<ui::LinuxInputMethodContext> CreateInputMethodContext(
       ui::LinuxInputMethodContextDelegate* delegate) const override;
 
   // gfx::LinuxFontDelegate:
   gfx::FontRenderParams GetDefaultFontRenderParams() const override;
   void GetDefaultFontDescription(
       std::string* family_out,
       int* size_pixels_out,
       int* style_out,
-      gfx::FontRenderParams* params_out) const override;
+      gfx::FontRenderParams* params_out) override;
 
   // ui::LinuxShellDialog:
   ui::SelectFileDialog* CreateSelectFileDialog(
       ui::SelectFileDialog::Listener* listener,
       ui::SelectFilePolicy* policy) const override;
 
   // ui::LinuxUI:
   void Initialize() override;
   gfx::Image GetThemeImageNamed(int id) const override;
   bool GetColor(int id, SkColor* color) const override;
@@ skipping 26 matching lines @@
   void RemoveWindowButtonOrderObserver(
       views::WindowButtonOrderObserver* observer) override;
   bool UnityIsRunning() override;
   NonClientMiddleClickAction GetNonClientMiddleClickAction() override;
   void NotifyWindowManagerStartupComplete() override;
 
   // ui::TextEditKeybindingDelegate:
   bool MatchEvent(const ui::Event& event,
                   std::vector<ui::TextEditCommandAuraLinux>* commands) override;
 
+  // ui::Views::LinuxUI:
+  void UpdateDeviceScaleFactor(float device_scale_factor) override;
+
  private:
   typedef std::map<int, SkColor> ColorMap;
   typedef std::map<int, color_utils::HSL> TintMap;
   typedef std::map<int, gfx::Image> ImageCache;
 
   // This method returns the colors webkit will use for the scrollbars. When no
   // colors are specified by the GTK+ theme, this function averages of the
   // thumb part and of the track colors.
   void GetScrollbarColors(GdkColor* thumb_active_color,
                           GdkColor* thumb_inactive_color,
@@ skipping 124 matching lines @@
   NonClientMiddleClickAction middle_click_action_;
 
   // Image cache of lazily created images.
   mutable ImageCache gtk_images_;
 
   // Used to override the native theme for a window. If no override is provided
   // or the callback returns NULL, Gtk2UI will default to a NativeThemeGtk2
   // instance.
   NativeThemeGetter native_theme_overrider_;
 
+  float device_scale_factor_;
+
   DISALLOW_COPY_AND_ASSIGN(Gtk2UI);
 };
 
 }  // namespace libgtk2ui
 
 // Access point to the GTK2 desktop system. This should be the only symbol that
 // is exported in the library; everything else should be used through the
 // interface, because eventually this .so will be loaded through dlopen at
 // runtime so our main binary can conditionally load GTK2 or GTK3 or EFL or
 // QT or whatever.
 LIBGTK2UI_EXPORT views::LinuxUI* BuildGtk2UI();
 
 #endif  // CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_