Allow getting _only_ personalized snippets for NTP.

components/ntp_snippets/ntp_snippets_fetcher.h

 // Copyright 2016 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 COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_
 
 #include <memory>
 #include <set>
 #include <string>
@@ skipping 34 matching lines @@
       void(const std::string&, const SuccessCallback&, const ErrorCallback&)>;
 
   using OptionalSnippets = base::Optional<NTPSnippet::PtrVector>;
   // |snippets| contains parsed snippets if a fetch succeeded. If problems
   // occur, |snippets| contains no value (no actual vector in base::Optional).
   // Error details can be retrieved using last_status().
   using SnippetsAvailableCallback =
       base::Callback<void(OptionalSnippets snippets)>;
 
   // Enumeration listing all possible outcomes for fetch attempts. Used for UMA
-  // histograms, so do not change existing values.
+  // histograms, so do not change existing values. Insert new value at the end,

[Marc Treib, 2016/05/12 13:57:59]

nit: values, plural.

+  // and update the histogram definition.
   enum class FetchResult {
     SUCCESS,
     EMPTY_HOSTS,
     URL_REQUEST_STATUS_ERROR,
     HTTP_ERROR,
     JSON_PARSE_ERROR,
     INVALID_SNIPPET_CONTENT_ERROR,
+    OAUTH_TOKEN_ERROR,
     RESULT_MAX
   };
 
   NTPSnippetsFetcher(
       SigninManagerBase* signin_manager,
       OAuth2TokenService* oauth2_token_service,
       scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
       const ParseJSONCallback& parse_json_callback,
       bool is_stable_channel);
   ~NTPSnippetsFetcher() override;
@@ skipping 19 matching lines @@
   const std::string& last_json() const {
     return last_fetch_json_;
   }
 
   // Overrides internal clock for testing purposes.
   void SetTickClockForTesting(std::unique_ptr<base::TickClock> tick_clock) {
     tick_clock_ = std::move(tick_clock);
   }
 
  private:
-  enum class Variant { kRestrictedPersonalized, kRestricted, kPersonalized };
+  enum class Personalization { kPersonal, kNonPersonal, kBoth };
 
   void FetchSnippetsImpl(const GURL& url,
                          const std::string& auth_header,
                          const std::string& request);
   std::string GetHostRestricts() const;
   bool UseHostRestriction() const;
   bool UseAuthentication() const;
   void FetchSnippetsNonAuthenticated();
   void FetchSnippetsAuthenticated(const std::string& account_id,
                                   const std::string& oauth_access_token);
@@ skipping 43 matching lines @@
 
   // The fetcher for downloading the snippets.
   std::unique_ptr<net::URLFetcher> url_fetcher_;
 
   // The callback to notify when new snippets get fetched.
   SnippetsAvailableCallback snippets_available_callback_;
 
   // Flag for picking the right (stable/non-stable) API key for Chrome Reader.
   bool is_stable_channel_;
 
-  // The variant of the fetching to use.
-  Variant variant_;
+  // The variant of the fetching to use, loaded from variation parameters.
+  Personalization personalization_;
+  // Should we apply host restriction? It is loaded from variation parameters.
+  bool use_host_restriction_;
 
   // Allow for an injectable tick clock for testing.
   std::unique_ptr<base::TickClock> tick_clock_;
 
   base::WeakPtrFactory<NTPSnippetsFetcher> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsFetcher);
 };
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_