Fix padding and touch effects in search engine dialog.

On pre-L devices, each item in the list of search engines had too much
top padding and no bottom padding. Also, on all devices, clicking a
search engine didn't show a ripple or highlight. Both of these bugs have
been fixed.

BUG=482193

Review URL: https://codereview.chromium.org/1109263004

Cr-Commit-Position: refs/heads/master@{#327522}

chrome/android/java/res/layout/search_engine.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- 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.
- -->
+     found in the LICENSE file. -->
 
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="wrap_content"
+    android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:orientation="vertical">
+    android:background="?android:attr/selectableItemBackground"
+    android:gravity="center_vertical"
+    android:orientation="horizontal"
+    android:paddingTop="6dp"
+    android:paddingBottom="6dp">
 
-    <LinearLayout
+    <RadioButton
+        android:id="@+id/radiobutton"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:orientation="horizontal"
-        android:layout_marginTop="22dp">
-        <RadioButton
-            android:id="@+id/radiobutton"
-            android:layout_width="27sp"
-            android:layout_height="23sp"
-            android:layout_marginStart="21dp"
-            android:layout_marginEnd="21dp" />
+        android:layout_marginStart="21dp"
+        android:layout_marginEnd="16dp" />
+
+    <LinearLayout
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:orientation="vertical">
         <TextView
             android:id="@+id/description"
             android:layout_width="wrap_content"
-            android:layout_height="match_parent"
+            android:layout_height="wrap_content"
             android:textSize="17sp" />
+        <TextView
+            android:id="@+id/link"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginEnd="21dp" />
     </LinearLayout>
 
-    <TextView
-        android:id="@+id/link"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_marginStart="70dp"
-        android:layout_marginEnd="21dp" />
 </LinearLayout>
\ No newline at end of file

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

@@ -89,7 +89,7 @@ public class SearchEngineAdapter extends BaseAdapter implements LoadListener, On
     }
 
     void setValueForTesting(String value) {
-        radioButtonClicked(Integer.parseInt(value));
+        searchEngineSelected(Integer.parseInt(value));
     }
 
     /**
@@ -164,22 +164,19 @@ public class SearchEngineAdapter extends BaseAdapter implements LoadListener, On
             view = mLayoutInflater.inflate(R.layout.search_engine, null);
         }
 
-        RadioButton radioButton = (RadioButton) view.findViewById(R.id.radiobutton);
-        TextView description = (TextView) view.findViewById(R.id.description);
-        TextView link = (TextView) view.findViewById(R.id.link);
-
-        TemplateUrl templateUrl = mSearchEngines.get(position);
-        Resources resources = mContext.getResources();
+        view.setOnClickListener(this);
+        view.setTag(position);
 
+        RadioButton radioButton = (RadioButton) view.findViewById(R.id.radiobutton);
         boolean selected = position == mSelectedSearchEnginePosition;
         radioButton.setChecked(selected);
-        radioButton.setOnClickListener(this);
-        radioButton.setTag(position);
 
+        TextView description = (TextView) view.findViewById(R.id.description);
+        TemplateUrl templateUrl = mSearchEngines.get(position);
+        Resources resources = mContext.getResources();
         description.setText(getSearchEngineNameAndDomain(resources, templateUrl));
-        description.setOnClickListener(this);
-        description.setTag(position);
 
+        TextView link = (TextView) view.findViewById(R.id.link);
         link.setVisibility(selected ? View.VISIBLE : View.GONE);
         if (selected) {
             ForegroundColorSpan linkSpan = new ForegroundColorSpan(
@@ -219,19 +216,17 @@ public class SearchEngineAdapter extends BaseAdapter implements LoadListener, On
         if (view.getTag() == null) {
             onLocationLinkClicked();
         } else {
-            radioButtonClicked((int) view.getTag());
+            searchEngineSelected((int) view.getTag());
         }
     }
 
-    private void radioButtonClicked(int position) {
+    private void searchEngineSelected(int position) {
         // First clean up any automatically added permissions (if any) for the previously selected
         // search engine.
         SharedPreferences sharedPreferences =
                 PreferenceManager.getDefaultSharedPreferences(mContext);
         if (sharedPreferences.getBoolean(PrefServiceBridge.LOCATION_AUTO_ALLOWED, false)) {
             if (locationEnabled(mSelectedSearchEnginePosition)) {
-                TemplateUrl templateUrl = mSearchEngines.get(mSelectedSearchEnginePosition);
-
                 String url = TemplateUrlService.getInstance().getSearchEngineUrlFromTemplateUrl(
                         toIndex(mSelectedSearchEnginePosition));
                 WebsitePreferenceBridge.nativeSetGeolocationSettingForOrigin(