Prerender: Disable prefetch if there's an appcache.

content/public/browser/appcache_service.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_APPCACHE_SERVICE_H_
 #define CONTENT_PUBLIC_BROWSER_APPCACHE_SERVICE_H_
 
 #include <map>
 #include <memory>
 #include <set>
 
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "content/public/common/appcache_info.h"
 #include "net/base/completion_callback.h"
 
+namespace net {
+class URLRequest;
+}  // namespace net
+
 namespace content {
 
 // Refcounted container to avoid copying the collection in callbacks.
 struct CONTENT_EXPORT AppCacheInfoCollection
     : public base::RefCountedThreadSafe<AppCacheInfoCollection> {
   AppCacheInfoCollection();
 
   std::map<GURL, AppCacheInfoVector> infos_by_origin;
 
  private:
@@ skipping 13 matching lines @@
                                   const net::CompletionCallback& callback) = 0;
 
   // Deletes the group identified by 'manifest_url', 'callback' is
   // invoked upon completion. Upon completion, the cache group and
   // any resources within the group are no longer loadable and all
   // subresource loads for pages associated with a deleted group
   // will fail. This method always completes asynchronously.
   virtual void DeleteAppCacheGroup(const GURL& manifest_url,
                                    const net::CompletionCallback& callback) = 0;
 
+  static bool URLRequestHasActiveAppCache(net::URLRequest* request);

[michaeln, 2017/03/27 23:27:45]

If we can avoid adding this to the content public api, we probably should.

+
  protected:
   virtual ~AppCacheService() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_APPCACHE_SERVICE_H_