[NTP Snippets] Refresh the displayed snippets less frequently

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetArticle.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetArticle.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetArticle.java
index f4c81f84d07acc219a0e4f0fc67260460467d352..9e68b0a14ba4484fe89a94eed388f60e55a990b6 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetArticle.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/snippets/SnippetArticle.java
@@ -45,6 +45,17 @@ public SnippetArticle(String title, String publisher, String previewText, String
     }
 
     @Override
+    public boolean equals(Object other) {
+        if (!(other instanceof SnippetArticle)) return false;
+        return mUrl.equals(((SnippetArticle) other).mUrl);
+    }
+
+    @Override
+    public int hashCode() {
+        return mUrl.hashCode();
+    }
+
+    @Override
     public int getType() {
         return NewTabPageListItem.VIEW_TYPE_SNIPPET;
     }
@@ -53,12 +64,12 @@ public int getType() {
      * Returns this article's tumbnail as a {@link Bitmap}. Can return {@code null} as it is
      * initially unset.
      */
-    Bitmap getThumbnailBitmap() {
+    public Bitmap getThumbnailBitmap() {
         return mThumbnailBitmap;
     }
 
     /** Sets the tumbnail bitmap for this article. */
-    void setThumbnailBitmap(Bitmap bitmap) {
+    public void setThumbnailBitmap(Bitmap bitmap) {
         mThumbnailBitmap = bitmap;
     }
 }