Let ActivityManager delete the remaining activities on shutdown.

athena/main/web_activity.cc

 // 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.
 
 #include "athena/main/web_activity.h"
 
 #include "athena/activity/public/activity_manager.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/web_contents.h"
 
 WebActivity::WebActivity(content::WebContents* contents)
     : content::WebContentsObserver(contents) {
 }
 
 WebActivity::~WebActivity() {
-  athena::ActivityManager::Get()->RemoveActivity(this);
 }
 
 athena::ActivityViewModel* WebActivity::GetActivityViewModel() {
   return this;
 }
 
 SkColor WebActivity::GetRepresentativeColor() {
   // TODO(sad): Compute the color from the favicon.
   return SK_ColorGRAY;
 }
 
 std::string WebActivity::GetTitle() {
   return base::UTF16ToUTF8(web_contents()->GetTitle());
 }
 
 aura::Window* WebActivity::GetNativeWindow() {
   return web_contents()->GetNativeView();
 }
 
 void WebActivity::TitleWasSet(content::NavigationEntry* entry,
                               bool explicit_set) {
   athena::ActivityManager::Get()->UpdateActivity(this);
 }
 
 void WebActivity::DidUpdateFaviconURL(
     const std::vector<content::FaviconURL>& candidates) {
   athena::ActivityManager::Get()->UpdateActivity(this);
 }