Reland: Ntp: restore scroll position.

content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java

Index: content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java b/content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java
index f4f35c6e6e3d21e420c0918ff73b879337e458e9..d23c38e43f1b82f5b5e357babe531ef91adec7cc 100644
--- a/content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java
+++ b/content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java
@@ -277,6 +277,18 @@ import org.chromium.content_public.common.ResourceRequestBody;
                 replaceEntry);
     }
 
+    @Override
+    public String getEntryExtraData(int index, String key) {
+        if (mNativeNavigationControllerAndroid == 0) return null;
+        return nativeGetEntryExtraData(mNativeNavigationControllerAndroid, index, key);
+    }
+
+    @Override
+    public void setEntryExtraData(int index, String key, String value) {
+        if (mNativeNavigationControllerAndroid == 0) return;
+        nativeSetEntryExtraData(mNativeNavigationControllerAndroid, index, key, value);
+    }
+
     @CalledByNative
     private static void addToNavigationHistory(Object history, Object navigationEntry) {
         ((NavigationHistory) history).addEntry((NavigationEntry) navigationEntry);
@@ -338,4 +350,8 @@ import org.chromium.content_public.common.ResourceRequestBody;
             long sourceNavigationControllerAndroid);
     private native void nativeCopyStateFromAndPrune(long nativeNavigationControllerAndroid,
             long sourceNavigationControllerAndroid, boolean replaceEntry);
+    private native String nativeGetEntryExtraData(
+            long nativeNavigationControllerAndroid, int index, String key);
+    private native void nativeSetEntryExtraData(
+            long nativeNavigationControllerAndroid, int index, String key, String value);
 }