added scale animation for context menu

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

Index: chrome/android/java/res/layout/tabular_context_menu.xml
diff --git a/chrome/android/java/res/layout/tabular_context_menu.xml b/chrome/android/java/res/layout/tabular_context_menu.xml
index 11998c6ed39020b97d1cfc6545f41ae002ae768d..be6c7ae2bc0b27757f1267f2090acc03e70fe54b 100644
--- a/chrome/android/java/res/layout/tabular_context_menu.xml
+++ b/chrome/android/java/res/layout/tabular_context_menu.xml
@@ -6,19 +6,21 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/custom_pager"
-    android:layout_width="wrap_content"
+    android:background="@drawable/white_with_rounded_corners"
+    android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_marginTop="20dp"
     android:layout_marginBottom="20dp"
     android:minWidth="280dp">
     <android.support.design.widget.TabLayout
         android:id="@+id/tab_layout"
-        android:layout_width="match_parent"
+        android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:background="@color/google_grey_100"
         app:tabTextColor="#80000000"
         app:tabSelectedTextColor="@color/light_active_color"
         app:tabIndicatorColor="@color/light_active_color"
         app:tabGravity="fill"
-        app:tabMode="fixed" />
+        app:tabMode="fixed"
+        app:tabMaxWidth="2000dp" />
 </org.chromium.chrome.browser.contextmenu.TabularContextMenuViewPager>