[Android] Hide description in RadioButtonWithDescription if it's empty

This CL adds a check to hide the description text view in
RadioButtonWithDescription if it contains an empty string.

Bug: 869426
Change-Id: I9e0b26303a0d98b2d44944818927f0acea5aaa59
Reviewed-on: https://chromium-review.googlesource.com/1159072Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580486}

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

@@ -21,6 +21,7 @@
         android:textColor="#de000000"
         android:textSize="16sp" />
 
+    <!-- This TextView is hidden if it has no text, so the initial visibility should be "gone". -->
     <TextView
         android:id="@+id/description"
         android:layout_width="wrap_content"
@@ -28,5 +29,6 @@
         android:layout_alignStart="@id/title"
         android:layout_below="@id/title"
         android:textColor="#8a000000"
-        android:textSize="14sp" />
+        android:textSize="14sp"
+        android:visibility="gone"/>
 </merge>

chrome/android/java/src/org/chromium/chrome/browser/widget/RadioButtonWithDescription.java

@@ -8,6 +8,7 @@ import android.content.Context;
 import android.content.res.TypedArray;
 import android.os.Bundle;
 import android.os.Parcelable;
+import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
@@ -85,6 +86,7 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
      */
     public void setDescriptionText(CharSequence text) {
         mDescription.setText(text);
+        mDescription.setVisibility(TextUtils.isEmpty(text) ? View.GONE : View.VISIBLE);
     }
 
     /**