Add implementation for Ad Networks Database

chrome/browser/extensions/activity_log/ad_injection_browsertest.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 "base/files/file_path.h"
 #include "base/scoped_observer.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/extensions/activity_log/activity_actions.h"
 #include "chrome/browser/extensions/activity_log/activity_log.h"
@@ skipping 73 matching lines @@
     ++injection_count_;
   }
 }
 
 // A mock for the AdNetworkDatabase. This simply says that the URL
 // http://www.known-ads.adnetwork is an ad network, and nothing else is.
 class TestAdNetworkDatabase : public AdNetworkDatabase {
  public:
   TestAdNetworkDatabase();
   virtual ~TestAdNetworkDatabase();
+
+ private:

[felt, 2014/04/23 03:01:36]

Is there any reason why the browsertest has different public/private than the
parent class?

[Devlin, 2014/04/23 18:16:55]

Yeah, it's a C++ trick that we commonly do in order to make sure that the only
time these methods are called is through the original implementation.  You can
see it frequently with classes implementing observers, so that only the
notifying class calls them.

+  // AdNetworkDatabase implementation.
+  virtual bool IsEnabled() const OVERRIDE { return true; }
   virtual bool IsAdNetwork(const GURL& url) const OVERRIDE;
 
- private:
   GURL ad_network_url_;
 };
 
 TestAdNetworkDatabase::TestAdNetworkDatabase() : ad_network_url_(kAdNetwork) {}
 TestAdNetworkDatabase::~TestAdNetworkDatabase() {}
 
 bool TestAdNetworkDatabase::IsAdNetwork(const GURL& url) const {
   return url == ad_network_url_;
 }
 
@@ skipping 229 matching lines @@
     listener()->Reply("Continue");
     listener()->Reset();
   }
 }
 
 // TODO(rdevlin.cronin): We test a good amount of ways of injecting ads with
 // the above test, but more is better in testing.
 // See crbug.com/357204.
 
 }  // namespace extensions