Resubmit: Add real file for AdNetworks DB

chrome/browser/extensions/activity_log/hashed_ad_network_database.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_HASHED_AD_NETWORK_DATABASE_H_
 #define CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_HASHED_AD_NETWORK_DATABASE_H_
 
 #include "base/containers/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/extensions/activity_log/ad_network_database.h"
 
 namespace base {
 class RefCountedStaticMemory;
 }
 
 namespace extensions {
 
 // The standard ("real") implementation of the AdNetworkDatabase, which stores
 // a list of hashes of ad networks.
 class HashedAdNetworkDatabase : public AdNetworkDatabase {
  public:
   explicit HashedAdNetworkDatabase(
       scoped_refptr<base::RefCountedStaticMemory> memory);
   virtual ~HashedAdNetworkDatabase();
 
+  bool is_valid() const { return is_valid_; }
+
  private:
   // AdNetworkDatabase implementation.
   virtual bool IsAdNetwork(const GURL& url) const OVERRIDE;
 
+  // Whether or not the database is valid, i.e., has correctly parsed the hash
+  // file. If it is not, it will always return false for IsAdNetwork(), since
+  // it cannot match against known hashes.
+  bool is_valid_;
+
   // The set of partial hashes for known ad networks.
   base::hash_set<int64> entries_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_HASHED_AD_NETWORK_DATABASE_H_