[Android] Sort custom search engines based on last visited time and display only top 3 most recentl…

chrome/android/java/src/org/chromium/chrome/browser/search_engines/TemplateUrlService.java

 // Copyright 2013 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.search_engines;
 
 import android.support.annotation.IntDef;
 import android.text.TextUtils;
 
 import org.chromium.base.ObserverList;
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 /**
@@ skipping 344 matching lines @@
 
     /**
      * Finds the URL for the search engine at the given index.
      * @param index The templateUrl index to look up.
      * @return      A {@link String} that contains the url of the specified search engine.
      */
     public String getSearchEngineUrlFromTemplateUrl(String keyword) {
         return nativeGetSearchEngineUrlFromTemplateUrl(mNativeTemplateUrlServiceAndroid, keyword);
     }
 
+    @VisibleForTesting
+    public String addSearchEngineForTesting(String keyword, int offset) {
+        return nativeAddSearchEngineForTesting(mNativeTemplateUrlServiceAndroid, keyword, offset);
+    }
+
+    @VisibleForTesting
+    public String updateLastVisitedForTesting(String keyword) {
+        return nativeUpdateLastVisitedForTesting(mNativeTemplateUrlServiceAndroid, keyword);
+    }
+
     private native long nativeInit();
     private native void nativeLoad(long nativeTemplateUrlServiceAndroid);
     private native boolean nativeIsLoaded(long nativeTemplateUrlServiceAndroid);
     private native int nativeGetTemplateUrlCount(long nativeTemplateUrlServiceAndroid);
     private native TemplateUrl nativeGetTemplateUrlAt(long nativeTemplateUrlServiceAndroid, int i);
     private native void nativeSetUserSelectedDefaultSearchProvider(
             long nativeTemplateUrlServiceAndroid, String selectedKeyword);
     private native int nativeGetDefaultSearchProviderIndex(long nativeTemplateUrlServiceAndroid);
     private native boolean nativeIsSearchProviderManaged(long nativeTemplateUrlServiceAndroid);
     private native boolean nativeIsSearchByImageAvailable(long nativeTemplateUrlServiceAndroid);
     private native boolean nativeIsDefaultSearchEngineGoogle(long nativeTemplateUrlServiceAndroid);
     private native String nativeGetUrlForSearchQuery(long nativeTemplateUrlServiceAndroid,
             String query);
     private native String nativeGetUrlForVoiceSearchQuery(long nativeTemplateUrlServiceAndroid,
             String query);
     private native String nativeReplaceSearchTermsInUrl(long nativeTemplateUrlServiceAndroid,
             String query, String currentUrl);
     private native String nativeGetUrlForContextualSearchQuery(long nativeTemplateUrlServiceAndroid,
             String query, String alternateTerm, boolean shouldPrefetch, String protocolVersion);
     private native String nativeGetSearchEngineUrlFromTemplateUrl(
             long nativeTemplateUrlServiceAndroid, String keyword);
+    private native String nativeAddSearchEngineForTesting(
+            long nativeTemplateUrlServiceAndroid, String keyword, int offset);
+    private native String nativeUpdateLastVisitedForTesting(
+            long nativeTemplateUrlServiceAndroid, String keyword);
 }