ui: Cleanup class/struct forward declarations

ui/android/java/res/layout/date_time_picker_dialog.xml

Index: ui/android/java/res/layout/date_time_picker_dialog.xml
diff --git a/ui/android/java/res/layout/date_time_picker_dialog.xml b/ui/android/java/res/layout/date_time_picker_dialog.xml
deleted file mode 100644
index 6240d35674092e63fe433bcca833ea9863ab4c8b..0000000000000000000000000000000000000000
--- a/ui/android/java/res/layout/date_time_picker_dialog.xml
+++ /dev/null
@@ -1,42 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2012 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.
--->
-
-<!-- ScrollView is needed since sometimes the dialog does not fit in small screen devices. -->
-<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="wrap_content"
-    android:layout_height="wrap_content">
-
-    <LinearLayout
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_gravity="center_horizontal"
-        android:orientation="vertical"
-        android:gravity="center">
-
-        <DatePicker
-            android:id="@+id/date_picker"
-            android:layout_gravity="center_horizontal"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:spinnersShown="true"
-            android:calendarViewShown="false"
-            android:datePickerMode="spinner"
-            android:contentDescription="@string/accessibility_datetime_picker_date"
-            />
-
-        <TimePicker
-            android:id="@+id/time_picker"
-            android:layout_gravity="center_horizontal"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:timePickerMode="spinner"
-            android:contentDescription="@string/accessibility_datetime_picker_time"
-            />
-
-    </LinearLayout>
-
-</ScrollView>