Add ButtonCompat: a Material-styled button on all versions of Android.

chrome/android/java/res/values-v17/styles.xml

Index: chrome/android/java/res/values-v17/styles.xml
diff --git a/chrome/android/java/res/values-v17/styles.xml b/chrome/android/java/res/values-v17/styles.xml
index 18f7f5677f7dc8b506291942e5d029fe9e32a258..dd61a6ccee6816d338deba4c0cae7ae0b260343d 100644
--- a/chrome/android/java/res/values-v17/styles.xml
+++ b/chrome/android/java/res/values-v17/styles.xml
@@ -184,4 +184,25 @@
         <item name="android:windowEnterAnimation">@anim/fullscreen_notification_in</item>
     </style>
 
+    <!-- Buttons -->
+    <style name="ButtonCompatBase">
+        <item name="android:minWidth">88dp</item>
+        <item name="android:minHeight">36dp</item>
+        <item name="android:textSize">14sp</item>
+        <item name="android:paddingStart">20dp</item>
+        <item name="android:paddingEnd">20dp</item>
+        <item name="android:paddingTop">5dp</item>
+        <item name="android:paddingBottom">5dp</item>
+        <item name="android:textAllCaps">true</item>
+        <item name="android:focusable">true</item>
+        <item name="android:clickable">true</item>
+        <item name="android:gravity">center_vertical|center_horizontal</item>
+    </style>
+    <style name="ButtonCompat" parent="ButtonCompatBase">
+        <item name="android:background">@drawable/button_compat_shape</item>
+    </style>
+    <style name="ButtonBorderlessCompat" parent="ButtonCompat">
+        <item name="android:background">?attr/selectableItemBackground</item>
+    </style>
+
 </resources>