AppCaches which belong to hosted apps are not protected from deletion

chrome/browser/profiles/profile.h

 // Copyright (c) 2011 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.
 
 // This class gathers state related to a single user profile.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "chrome/common/extensions/extension.h"
 
 namespace base {
 class Time;
+class WaitableEvent;
 }
 
 namespace content {
 class ResourceContext;
 }
 
 namespace fileapi {
 class FileSystemContext;
 class SandboxedFileSystemContext;
 }
@@ skipping 479 matching lines @@
 #endif  // defined(OS_CHROMEOS)
 
   // Returns the helper object that provides the proxy configuration service
   // access to the the proxy configuration possibly defined by preferences.
   virtual PrefProxyConfigTracker* GetProxyConfigTracker() = 0;
 
   // Returns the PrerenderManager used to prerender entire webpages for this
   // profile.
   virtual prerender::PrerenderManager* GetPrerenderManager() = 0;
 
+  // Clears the app cache (if the profile settings to dictate), returns a
+  // WaitableEvent for signalling when the clearing is complete, or NULL if
+  // there is nothing to clear. The WaitableEvent is not owned by the caller.
+  virtual base::WaitableEvent* ClearAppCache();
+
   std::string GetDebugName();
 
   // Returns whether it is a guest session.
   static bool IsGuestSession();
 
 #ifdef UNIT_TEST
   // Use with caution.  GetDefaultRequestContext may be called on any thread!
   static void set_default_request_context(net::URLRequestContextGetter* c) {
     default_request_context_ = c;
   }
@@ skipping 39 matching lines @@
   bool restored_last_session_;
 
   // Accessibility events will only be propagated when the pause
   // level is zero.  PauseAccessibilityEvents and ResumeAccessibilityEvents
   // increment and decrement the level, respectively, rather than set it to
   // true or false, so that calls can be nested.
   int accessibility_pause_level_;
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_H_