Create the base Custom Context Menu Dialog.

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

Index: chrome/android/java/res/layout/custom_context_menu.xml
diff --git a/chrome/android/java/res/layout/custom_context_menu.xml b/chrome/android/java/res/layout/custom_context_menu.xml
new file mode 100644
index 0000000000000000000000000000000000000000..eeb60e32491af9847f27c58ac105e7d85fd17cbf
--- /dev/null
+++ b/chrome/android/java/res/layout/custom_context_menu.xml
@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/content_layer"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:minWidth="280dp"
+    android:orientation="vertical">
+
+    <FrameLayout
+        android:layout_marginTop="20dp"
+        android:layout_marginStart="20dp"
+        android:layout_marginEnd="20dp"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="10dp"
+        android:layout_gravity="center">
+        <TextView
+            android:id="@+id/context_header_text"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:gravity="center"
+            android:maxLines="1"
+            android:textSize="13sp"
+            android:textStyle="bold"
+            android:ellipsize="end"
+            android:visibility="gone"/>
+        <ImageView
+            android:id="@+id/context_header_image"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:contentDescription="@string/context_menu_header_image_default_desc_text"
+            android:background="@drawable/custom_context_menu_checkerboard_image_background"
+            android:foreground="@drawable/custom_context_menu_image_border"
+            android:minWidth="54dp"
+            android:minHeight="54dp"
+            android:visibility="gone"/>
+    </FrameLayout>
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="1dp"
+        android:background="#1e000000"/>
+
+    <ListView
+        android:id="@+id/selectable_items"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:paddingTop="8dp"
+        android:paddingBottom="8dp"
+        android:dividerHeight="0dp"
+        android:divider="@null"/>
+</LinearLayout>