Ntp: restore scroll position.

content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java

Index: content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java
diff --git a/content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java b/content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java
index b818a93dc41e4b95402ce2b7d76dbe8368c2e39c..178fa2432120a1c1c798d00c3bcadb55284befe6 100644
--- a/content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java
+++ b/content/public/android/java/src/org/chromium/content_public/browser/NavigationEntry.java
@@ -6,6 +6,9 @@ package org.chromium.content_public.browser;
 
 import android.graphics.Bitmap;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * Represents one entry in the navigation history of a page.
  */
@@ -18,12 +21,14 @@ public class NavigationEntry {
     private final String mTitle;
     private Bitmap mFavicon;
     private int mTransition;
+    private final Map<String, String> mExtraData = new HashMap<>();
 
     /**
      * Default constructor.
      */
     public NavigationEntry(int index, String url, String virtualUrl, String originalUrl,
-            String title, Bitmap favicon, int transition) {
+            String title, Bitmap favicon, int transition, String[] extraDataKeys,
+            String[] extraDataValues) {
         mIndex = index;
         mUrl = url;
         mVirtualUrl = virtualUrl;
@@ -31,6 +36,11 @@ public class NavigationEntry {
         mTitle = title;
         mFavicon = favicon;
         mTransition = transition;
+
+        assert extraDataKeys.length == extraDataValues.length;
+        for (int i = 0; i < extraDataKeys.length; i++) {
+            mExtraData.put(extraDataKeys[i], extraDataValues[i]);
+        }
     }
 
     /**
@@ -98,4 +108,11 @@ public class NavigationEntry {
     public int getTransition() {
         return mTransition;
     }
+
+    /**
+     * @return The data value stored for {@code key}, or null if there is no data.
+     */
+    public String getExtraData(String key) {
+        return mExtraData.get(key);
+    }
 }