[Android] Handle different phones using different layouts for PreferenceFragment

chrome/android/java/src/org/chromium/chrome/browser/preferences/SearchEnginePreference.java

 // Copyright 2016 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.preferences;
 
 import android.os.Bundle;
 import android.preference.PreferenceFragment;
-import android.widget.LinearLayout.LayoutParams;
+import android.view.ViewGroup.LayoutParams;
+import android.widget.FrameLayout;
+import android.widget.LinearLayout;
 import android.widget.ListView;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.R;
 
 /**
 * A preference fragment for selecting a default search engine.
 */
 public class SearchEnginePreference extends PreferenceFragment {
     private ListView mListView;
@@ skipping 21 matching lines @@
         getActivity().setTitle(R.string.prefs_search_engine);
         mSearchEngineAdapter = new SearchEngineAdapter(getActivity());
     }
 
     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
         mListView = (ListView) getView().findViewById(android.R.id.list);
         int marginTop = getActivity().getResources().getDimensionPixelSize(
                 R.dimen.search_engine_list_margin_top);
-        LayoutParams layoutParams =
-                new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
-        layoutParams.setMargins(0, marginTop, 0, 0);
+        LayoutParams layoutParams = mListView.getLayoutParams();
+        if (layoutParams instanceof FrameLayout.LayoutParams) {
+            ((FrameLayout.LayoutParams) layoutParams).setMargins(0, marginTop, 0, 0);

[gone, 2016/12/02 22:39:55]

Don't need to do this.  Both FrameLayout.LayoutParams and
LinearLayout.LayoutParams inherit from MarginLayoutParams:

https://developer.android.com/reference/android/view/ViewGroup.MarginLayoutPa...

[ltian, 2016/12/02 23:09:04]

Done.

+        } else {
+            ((LinearLayout.LayoutParams) layoutParams).setMargins(0, marginTop, 0, 0);
+        }
         mListView.setLayoutParams(layoutParams);
         mListView.setAdapter(mSearchEngineAdapter);
         mListView.setDivider(null);
     }
 
     @Override
     public void onResume() {
         super.onResume();
         /**
          * Handle UI update when location setting for a search engine is changed.
          */
         mSearchEngineAdapter.notifyDataSetChanged();
     }
 }