Fix layout of prefs of distilled page viewer

Make sure all elements are displayed fully.

Bug: 794733
Change-Id: Ib4c8082d16e9445861da77774309ffc26d2cf27b
Reviewed-on: https://chromium-review.googlesource.com/826463Reviewed-by: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524284}

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

@@ -52,7 +52,7 @@
         <TextView
             android:id="@+id/font_size_percentage"
             android:layout_width="wrap_content"
-            android:layout_height="match_parent"
+            android:layout_height="wrap_content"
             android:layout_marginEnd="3dp"
             android:layout_marginStart="3dp"
             android:minWidth="50dp"
@@ -61,7 +61,7 @@
 
         <TextView
             android:layout_width="wrap_content"
-            android:layout_height="match_parent"
+            android:layout_height="wrap_content"
             android:gravity="center_vertical"
             android:layout_marginStart="5dp"
             android:textSize="13sp"
@@ -71,13 +71,14 @@
             android:id="@+id/font_size"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
+            android:layout_gravity="center"
             android:layout_weight="1"
             android:orientation="horizontal"
             android:max="30" />
 
         <TextView
             android:layout_width="wrap_content"
-            android:layout_height="match_parent"
+            android:layout_height="wrap_content"
             android:gravity="center_vertical"
             android:layout_marginEnd="3dp"
             android:textSize="20sp"