[linux] Allow font to use below 1.0f scale

chrome/browser/ui/libgtkui/gtk_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_LIBGTKUI_GTK_UI_H_
 #define CHROME_BROWSER_UI_LIBGTKUI_GTK_UI_H_
 
 #include <map>
 #include <memory>
 #include <vector>
@@ skipping 87 matching lines @@
       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;
+  void UpdateDeviceScaleFactor() override;
   float GetDeviceScaleFactor() const override;
 
  private:
   typedef std::map<int, SkColor> ColorMap;
   typedef std::map<int, color_utils::HSL> TintMap;
 
   // 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 SetScrollbarColors();
@@ skipping 44 matching lines @@
   SkColor thumb_active_color_;
   SkColor thumb_inactive_color_;
   SkColor track_color_;
   SkColor active_selection_bg_color_;
   SkColor active_selection_fg_color_;
   SkColor inactive_selection_bg_color_;
   SkColor inactive_selection_fg_color_;
 
   // Details about the default UI font.
   std::string default_font_family_;
-  int default_font_size_pixels_;
-  int default_font_style_;  // Bitfield of gfx::Font::Style values.
-  gfx::Font::Weight default_font_weight_;
+  int default_font_size_pixels_ = 0;
+  // Bitfield of gfx::Font::Style values.
+  int default_font_style_ = gfx::Font::NORMAL;
+  gfx::Font::Weight default_font_weight_ = gfx::Font::Weight::NORMAL;
   gfx::FontRenderParams default_font_render_params_;
 
 #if defined(USE_GCONF)
   // Currently, the only source of window button configuration. This will
   // change if we ever have to support XFCE's configuration system or KDE's.
   std::unique_ptr<GConfListener> gconf_listener_;
 #endif  // defined(USE_GCONF)
 
   // If either of these vectors are non-empty, they represent the current
   // window button configuration.
   std::vector<views::FrameButton> leading_buttons_;
   std::vector<views::FrameButton> trailing_buttons_;
 
   std::unique_ptr<Gtk2KeyBindingsHandler> key_bindings_handler_;
 
   // Objects to notify when the window frame button order changes.
   base::ObserverList<views::WindowButtonOrderObserver> observer_list_;
 
   // Whether we should lower the window on a middle click to the non client
   // area.
   NonClientMiddleClickAction middle_click_action_;
 
   // 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_;
+  float device_scale_factor_ = 1.0f;
 
   DISALLOW_COPY_AND_ASSIGN(Gtk2UI);
 };
 
 }  // namespace libgtkui
 
 // 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.
 LIBGTKUI_EXPORT views::LinuxUI* BuildGtk2UI();
 
 #endif  // CHROME_BROWSER_UI_LIBGTKUI_GTK_UI_H_