Use ButtonCompat to get Material-y buttons in more places.

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

Index: chrome/android/java/res/layout/preference_button.xml
diff --git a/chrome/android/java/res/layout/preference_button.xml b/chrome/android/java/res/layout/preference_button.xml
index eba69f7d274e1cfb3735732ec98d49988763c313..6d94d4b6eb53183fdc1e48a05a5a024f3238ef90 100644
--- a/chrome/android/java/res/layout/preference_button.xml
+++ b/chrome/android/java/res/layout/preference_button.xml
@@ -5,21 +5,22 @@
 
 <!-- Layout used by ButtonPreference for the button widget style. -->
 
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:chrome="http://schemas.android.com/apk/res-auto"
     style="@style/PreferenceLayout"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:clipToPadding="false"
     android:gravity="center_vertical"
     android:orientation="vertical">
 
-    <Button
+    <org.chromium.chrome.browser.widget.ButtonCompat
         android:id="@+id/button_preference"
         android:layout_height="wrap_content"
         android:layout_width="wrap_content"
-        android:layout_marginStart="@dimen/pref_button_margin_start"
-        android:paddingStart="@dimen/pref_button_horizontal_padding"
-        android:paddingEnd="@dimen/pref_button_horizontal_padding"
-        android:paddingTop="@dimen/pref_button_vertical_padding"
-        android:paddingBottom="@dimen/pref_button_vertical_padding" />
+        android:minHeight="40dp"
+        android:textColor="#fff"
+        chrome:buttonColor="@color/pref_accent_color" />
 
 </LinearLayout>