NTP: Fix metrics recording crash by plumbing the necessary data to Java.

components/ntp_tiles/most_visited_sites.h

 // Copyright 2013 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_TILES_MOST_VISITED_SITES_H_
 #define COMPONENTS_NTP_TILES_MOST_VISITED_SITES_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 77 matching lines @@
 // in C++.
 //
 // TODO(sfiera): finalize interface.
 class MostVisitedSites : public history::TopSitesObserver,
                          public MostVisitedSitesSupervisor::Observer {
  public:
   struct Suggestion;
   using SuggestionsVector = std::vector<Suggestion>;
   using PopularSitesVector = std::vector<PopularSites::Site>;
 
+  // The visual type of a most visited tile.
+  //
+  // These values must stay in sync with the MostVisitedTileType enum
+  // in histograms.xml.
+  //
+  // A Java counterpart will be generated for this enum.
+  // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser.ntp
+  enum MostVisitedTileType {
+    // The icon or thumbnail hasn't loaded yet.
+    NONE,
+    // The item displays a site's actual favicon or touch icon.
+    ICON_REAL,
+    // The item displays a color derived from the site's favicon or touch icon.
+    ICON_COLOR,
+    // The item displays a default gray box in place of an icon.
+    ICON_DEFAULT,
+    NUM_TILE_TYPES,
+  };

[Marc Treib, 2016/06/29 08:19:32]

Any particular reason for moving this into the header?

[dewittj, 2016/06/30 17:48:54]

A few reasons.  This enum is exposed to Java, making it semi-public already. 
Also, the gypi build file appears to take only one source file, so I preferred
to have it scan the .h than to make two rules, one for the .h and one for the
.cc

[Marc Treib, 2016/07/01 10:01:03]

Acknowledged.

+
   // The source of the Most Visited sites.
-  enum MostVisitedSource { TOP_SITES, SUGGESTIONS_SERVICE, POPULAR, WHITELIST };
+  // A Java counterpart will be generated for this enum.
+  // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser.ntp
+  enum MostVisitedSource {
+    // Item comes from the regional top sites list.

[Marc Treib, 2016/06/29 08:19:32]

Nope, these are the *personal* top sites.

[Bernhard Bauer, 2016/06/29 10:17:43]

(The regional ones are called "popular sites" 😃)

[dewittj, 2016/06/30 17:48:54]

Done.

+    TOP_SITES,
+    // Item comes from the suggestions service.
+    SUGGESTIONS_SERVICE,
+    // Item is most popular.

[Marc Treib, 2016/06/29 08:19:32]

These are the regionally popular ones.

[dewittj, 2016/06/30 17:48:54]

Done.

+    POPULAR,
+    // Item on static whitelist

[Marc Treib, 2016/06/29 08:19:32]

s/static/supervised user/ ?
(These whitelists exist only for supervised users, and I don't know what
"static" is supposed to mean)

[dewittj, 2016/06/30 17:48:54]

Done.

+    WHITELIST
+  };
 
   // The observer to be notified when the list of most visited sites changes.
   class Observer {
    public:
     virtual void OnMostVisitedURLsAvailable(
         const SuggestionsVector& suggestions) = 0;
     virtual void OnPopularURLsAvailable(const PopularSitesVector& sites) = 0;
 
    protected:
     virtual ~Observer() {}
@@ skipping 32 matching lines @@
 
   ~MostVisitedSites() override;
 
   // Does not take ownership of |observer|, which must outlive this object and
   // must not be null.
   void SetMostVisitedURLsObserver(Observer* observer, int num_sites);
 
   using ThumbnailCallback = base::Callback<
       void(bool /* is_local_thumbnail */, const SkBitmap* /* bitmap */)>;
   void AddOrRemoveBlacklistedUrl(const GURL& url, bool add_url);
-  void RecordTileTypeMetrics(const std::vector<int>& tile_types);
   void RecordOpenedMostVisitedItem(int index, int tile_type);
 
   // MostVisitedSitesSupervisor::Observer implementation.
   void OnBlockedSitesChanged() override;
 
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
  private:
   friend class MostVisitedSitesTest;
 
@@ skipping 99 matching lines @@
 
   // For callbacks may be run after destruction.
   base::WeakPtrFactory<MostVisitedSites> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MostVisitedSites);
 };
 
 }  // namespace ntp_tiles
 
 #endif  // COMPONENTS_NTP_TILES_MOST_VISITED_SITES_H_