Remove unused themes on clicking the reset theme button

chrome/browser/themes/theme_service.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/themes/theme_service.h"
 
 #include "base/bind.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/prefs/pref_service.h"
 #include "base/sequenced_task_runner.h"
@@ skipping 287 matching lines @@
   return ThemeProperties::GetDefaultTint(id);
 }
 
 void ThemeService::ClearAllThemeData() {
   // Clear our image cache.
   FreePlatformCaches();
   theme_pack_ = NULL;
 
   profile_->GetPrefs()->ClearPref(prefs::kCurrentThemePackFilename);
   SaveThemeID(kDefaultThemeID);
+
+  RemoveUnusedThemes();
 }
 
 void ThemeService::LoadThemePrefs() {
   PrefService* prefs = profile_->GetPrefs();
 
   std::string current_id = GetThemeID();
   if (current_id == kDefaultThemeID) {
     set_ready();
     return;
   }
@@ skipping 104 matching lines @@
 void ThemeService::OnInfobarDestroyed() {
   number_of_infobars_--;
 
   if (number_of_infobars_ == 0)
     RemoveUnusedThemes();
 }
 
 ThemeSyncableService* ThemeService::GetThemeSyncableService() const {
   return theme_syncable_service_.get();
 }