Refactor and extend SnippetsBridge for multi-section support

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/ContentSuggestionsSource.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/ContentSuggestionsSource.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/ContentSuggestionsSource.java
new file mode 100644
index 0000000000000000000000000000000000000000..22d0252aa85ae72279584e5d4009b398539d6ccf
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/ContentSuggestionsSource.java
@@ -0,0 +1,74 @@
+// 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;
+import org.chromium.chrome.browser.ntp.snippets.CategoryStatus.CategoryStatusEnum;
+import org.chromium.chrome.browser.ntp.snippets.KnownCategories.KnownCategoriesEnum;
+
+import java.util.List;
+
+/**
+ * An interface for classes that provide content suggestions.
+ */
+public interface ContentSuggestionsSource {
+    /**
+     * An observer for events in the content suggestions service.
+     */
+    interface SnippetsObserver {
+        /** Called when a category has a new list of content suggestions. */
+        void onNewSuggestions(@KnownCategoriesEnum int category);
+
+        /** Called when a category changed its status. */
+        void onCategoryStatusChanged(
+                @KnownCategoriesEnum int category, @CategoryStatusEnum int newStatus);
+    }
+
+    /**
+     * Gets the categories in the order in which they should be displayed.
+     * @return The categories.
+     */
+    int[] getCategories();
+
+    /**
+     * Gets the status of a category, possibly indicating the reason why it is disabled.
+     */
+    @CategoryStatusEnum
+    int getCategoryStatus(int category);
+
+    /**
+     * Gets the meta information of a category.
+     */
+    SuggestionsCategoryInfo getCategoryInfo(int category);
+
+    /**
+     * Gets the current content suggestions for a category, in the order in which they should be
+     * displayed.
+     */
+    List<SnippetArticleListItem> getSuggestionsForCategory(int category);
+
+    /**
+     * Fetches the thumbnail image for a content suggestion.
+     */
+    void fetchSuggestionImage(SnippetArticleListItem suggestion, Callback<Bitmap> callback);
+
+    /**
+     * Tells the source to dismiss the content suggestion.
+     */
+    void dismissSuggestion(SnippetArticleListItem suggestion);
+
+    /**
+     * Checks whether a content suggestion has been visited.
+     */
+    void getSuggestionVisited(SnippetArticleListItem suggestion, Callback<Boolean> callback);
+
+    /**
+     * Sets the recipient for update events from the source.
+     */
+    void setObserver(SnippetsObserver observer);
+}