[Content suggestions] Add a function to the service API to fetch favicons

chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SuggestionsSource.java

 // 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.
 
 package org.chromium.chrome.browser.ntp.snippets;
 
 import android.graphics.Bitmap;
 
 import org.chromium.base.Callback;
 import org.chromium.chrome.browser.ntp.cards.SuggestionsCategoryInfo;
@@ skipping 58 matching lines @@
      */
     List<SnippetArticle> getSuggestionsForCategory(int category);
 
     /**
      * Fetches the thumbnail image for a content suggestion. A null Bitmap is returned if no image
      * is available. The callback is never called synchronously.
      */
     void fetchSuggestionImage(SnippetArticle suggestion, Callback<Bitmap> callback);
 
     /**
+     * Fetches the favicon for a content suggestion. A null Bitmap is returned if no good favicon is
+     * available. The callback is never called synchronously.
+     * @param suggestion The suggestion which the favicon should represent.
+     * @param minimumSizePx Minimal required size, if only a smaller favicon is available, a null
+     * Bitmap is returned.
+     * @param desiredSizePx If set to 0, it denotes that the favicon should be returned in its
+     * original size (as in favicon cache) without being resized. If not 0, it must be larger or
+     * equal to the minimum size and the favicon will be returned resized to this size.
+     * @param callback The callback that receives the favicon image.
+     */
+    void fetchSuggestionFavicon(SnippetArticle suggestion, int minimumSizePx, int desiredSizePx,
+            Callback<Bitmap> callback);
+
+    /**
      * Fetches new suggestions.
      * @param category the category to fetch new suggestions for.
      * @param displayedSuggestionIds ids of suggestions already known and that we want to keep.
      */
     void fetchSuggestions(@CategoryInt int category, String[] displayedSuggestionIds);
 
     /**
      * Tells the source to dismiss the content suggestion.
      */
     void dismissSuggestion(SnippetArticle suggestion);
 
     /**
      * Tells the source to dismiss the category.
      */
     void dismissCategory(@CategoryInt int category);
 
     /**
      * Restores all categories previously dismissed with {@link #dismissCategory}.
      */
     void restoreDismissedCategories();
 
     /**
      * Sets the recipient for update events from the source.
      */
     void setObserver(Observer observer);
-}
+}