Move each permission classes to its own files in extensions/permissions

chrome/browser/extensions/extension_font_settings_api.cc

Index: chrome/browser/extensions/extension_font_settings_api.cc
diff --git a/chrome/browser/extensions/extension_font_settings_api.cc b/chrome/browser/extensions/extension_font_settings_api.cc
index e8a0c39f7dce6fbd2e334d726fcd11858126e5d2..f3bc3e40c78f2693a85eaa76cd2dd4dc77b3f601 100644
--- a/chrome/browser/extensions/extension_font_settings_api.cc
+++ b/chrome/browser/extensions/extension_font_settings_api.cc
@@ -30,6 +30,8 @@
 #include "ui/gfx/platform_font_win.h"
 #endif
 
+using extensions::APIPermission;
+
 namespace fonts = extensions::api::experimental_font_settings;
 
 namespace {
@@ -210,7 +212,7 @@ void ExtensionFontSettingsEventRouter::OnFontNamePrefChanged(
       profile_,
       kOnFontChanged,
       &args,
-      ExtensionAPIPermission::kExperimental,
+      APIPermission::kExperimental,
       incognito,
       pref_name);
 }
@@ -234,7 +236,7 @@ void ExtensionFontSettingsEventRouter::OnFontPrefChanged(
       profile_,
       event_name,
       &args,
-      ExtensionAPIPermission::kExperimental,
+      APIPermission::kExperimental,
       incognito,
       pref_name);
 }