Upstream accessibility font size preferences.

chrome/browser/accessibility/font_size_prefs.h

+// Copyright (c) 2014 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_ACCESSIBILITY_FONT_SIZE_PREFS_H_
+#define CHROME_BROWSER_ACCESSIBILITY_FONT_SIZE_PREFS_H_
+
+#include "base/observer_list.h"
+
+class PrefChangeRegistrar;
+class PrefService;
+class Profile;
+
+class FontSizePrefs {
+ public:
+  class Observer {
+   public:
+    virtual void OnChangeFontSize(float font) = 0;
+    virtual void OnChangeForceEnableZoom(bool enabled) = 0;
+  };
+
+  explicit FontSizePrefs(Profile* profile);
+  ~FontSizePrefs();
+  void Destroy();
+
+  // Sets the font scale factor.
+  void SetFontScaleFactor(float font);
+  float GetFontScaleFactor();
+  // Callback for FontScaleFactor changes from pref change registrar.
+  void OnFontScaleFactorPrefsChanged();

[robliao, 2014/07/25 16:49:19]

These feel like they should be in a separate observer class.

[sunangel, 2014/07/25 19:22:56]

Made them private instead. 
Is the spacing okay between them?
On 2014/07/25 16:49:19, robliao wrote:

+
+  // Sets Force Enable Zoom.
+  void SetForceEnableZoom(bool enabled);
+  bool GetForceEnableZoom();
+  // Callback for ForceEnableZoom changes from pref change registrar.
+  void OnForceEnableZoomPrefsChanged();
+
+  void AddObserver(Observer* obs);
+  void RemoveObserver(Observer* obs);
+
+ private:
+  scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
+  PrefService* pref_service_;
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(FontSizePrefs);
+};
+
+#endif  // CHROME_BROWSER_ACCESSIBILITY_FONT_SIZE_PREFS_H_