Fix Pango font rendering with HiDPi displays on Linux.

chrome/browser/ui/libgtk2ui/gtk2_ui.h

Index: chrome/browser/ui/libgtk2ui/gtk2_ui.h
diff --git a/chrome/browser/ui/libgtk2ui/gtk2_ui.h b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
index d936d89584d3cd42b7d0051e78b00f1247477d1e..8fc7de4518d2937c5a3c4f395742261c30b01a6a 100644
--- a/chrome/browser/ui/libgtk2ui/gtk2_ui.h
+++ b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
@@ -25,6 +25,7 @@ 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;
 
@@ -71,7 +72,7 @@ class Gtk2UI : public views::LinuxUI {
       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(
@@ -118,6 +119,9 @@ class Gtk2UI : public views::LinuxUI {
   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;
@@ -262,6 +266,8 @@ class Gtk2UI : public views::LinuxUI {
   // instance.
   NativeThemeGetter native_theme_overrider_;
 
+  float device_scale_factor_;
+
   DISALLOW_COPY_AND_ASSIGN(Gtk2UI);
 };