Added a UI for the Interests Prototype.

chrome/android/java/src/org/chromium/chrome/browser/ntp/InterestsService.java

 // Copyright 2015 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;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.chrome.browser.profiles.Profile;
 
 /**
  * Retrieve the user's interests.
  */
 public class InterestsService {
+
     private long mNativeInterestsService;
 
     /**
      * A user's interest.
      */
     public static class Interest {
         private final String mName;
         private final String mImageUrl;
         private final double mRelevance;
 
@@ skipping 40 matching lines @@
     /**
      * Cleans up the C++ side of this class. This instance must not be used after calling destroy().
      */
     public void destroy() {
         assert mNativeInterestsService != 0;
         nativeDestroy(mNativeInterestsService);
         mNativeInterestsService = 0;
     }
 
     public void getInterests(final GetInterestsCallback callback) {
         GetInterestsCallback wrappedCallback = new GetInterestsCallback() {

[knn, 2015/12/02 13:30:43]

This doesn't seem to do anything. Moreover since the C++ object is controlled
from java and the callback itself is controlled by the C++ object (weak pointer)
we don't need anything here. Remove?

[PEConn, 2015/12/08 17:27:50]

Done.

             @Override
             public void onInterestsAvailableCallback(Interest[] interests) {
                 callback.onInterestsAvailableCallback(interests);
             }
         };
 
         nativeGetInterests(mNativeInterestsService, wrappedCallback);
     }
 
     /*
      * Helper methods for the native part.
      */
     @CalledByNative
     private static Interest createInterest(String name, String imageUrl, double relevance) {
         return new Interest(name, imageUrl, relevance);
     }
 
     @CalledByNative
     private static Interest[] createInterestsArray(int size) {
         return new Interest[size];
     }
 
     private native long nativeInit(Profile profile);
     private native void nativeDestroy(long nativeInterestsService);
     private native void nativeGetInterests(
             long nativeInterestsService, GetInterestsCallback callback);
 }