Fix IWYU violators that don't include scoped_ptr.h in Android build.

chrome/browser/android/accessibility/font_size_prefs_android.h

 // Copyright 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_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_
 
 #include <jni.h>
+
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 
 class PrefChangeRegistrar;
 class PrefService;
 
 /*
  * Native implementation of FontSizePrefs. This class is used to get and set
  * FontScaleFactor and ForceEnableZoom.
  */
 class FontSizePrefsAndroid {
@@ skipping 56 matching lines @@
 
   // FontSizePrefs::Observer implementation.
   void OnChangeFontSize(float font) override;
   void OnChangeForceEnableZoom(bool enabled) override;
 
  private:
   base::android::ScopedJavaGlobalRef<jobject> java_ref_;
 };
 
 #endif  // CHROME_BROWSER_ANDROID_ACCESSIBILITY_FONT_SIZE_PREFS_ANDROID_H_