[Android][WebSignin] Extract account picker header for reuse

This CL extracts the account picker bottom sheet header in a separate
file to reuse it in different account picker view xml files after the
refactoring.

Bug: 1138824
Change-Id: I025c9aac45ca5022a6b95d4ba3d847120d7cf3b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2502588Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821688}

chrome/android/chrome_java_resources.gni

@@ -775,6 +775,7 @@ chrome_java_resources = [
   "java/res/layout/account_chooser_dialog_title.xml",
   "java/res/layout/account_divider_preference.xml",
   "java/res/layout/account_management_account_row.xml",
+  "java/res/layout/account_picker_bottom_sheet_header.xml",
   "java/res/layout/account_picker_bottom_sheet_view.xml",
   "java/res/layout/account_picker_dialog_body.xml",
   "java/res/layout/account_picker_incognito_row.xml",

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

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 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. -->
+
+<merge
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:android="http://schemas.android.com/apk/res/android" >
+
+  <ImageView
+      android:id="@+id/account_picker_bottom_sheet_logo"
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:layout_gravity="center_horizontal"
+      android:importantForAccessibility="no"
+      app:srcCompat="@drawable/chrome_sync_logo" />
+
+  <TextView
+      android:id="@+id/account_picker_bottom_sheet_title"
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:layout_marginTop="12dp"
+      android:layout_marginBottom="8dp"
+      android:gravity="center_horizontal"
+      android:textAppearance="@style/TextAppearance.TextLarge.Primary"
+      android:text="@string/signin_account_picker_dialog_title" />
+
+  <org.chromium.ui.widget.TextViewWithLeading
+      android:id="@+id/account_picker_bottom_sheet_subtitle"
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:layout_marginStart="24dp"
+      android:layout_marginEnd="24dp"
+      android:layout_marginBottom="16dp"
+      android:gravity="center_horizontal"
+      android:textAppearance="@style/TextAppearance.TextMedium.Secondary"
+      android:text="@string/signin_account_picker_bottom_sheet_subtitle"
+      app:leading="@dimen/text_size_medium_leading" />
+</merge>
\ No newline at end of file

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

@@ -20,35 +20,7 @@
         android:importantForAccessibility="no"
         app:srcCompat="@drawable/drag_handlebar" />
 
-    <ImageView
-        android:id="@+id/account_picker_bottom_sheet_logo"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_gravity="center_horizontal"
-        android:importantForAccessibility="no"
-        app:srcCompat="@drawable/chrome_sync_logo" />
-
-    <TextView
-        android:id="@+id/account_picker_bottom_sheet_title"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_marginTop="12dp"
-        android:layout_marginBottom="8dp"
-        android:gravity="center_horizontal"
-        android:textAppearance="@style/TextAppearance.TextLarge.Primary"
-        android:text="@string/signin_account_picker_dialog_title" />
-
-    <org.chromium.ui.widget.TextViewWithLeading
-        android:id="@+id/account_picker_bottom_sheet_subtitle"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:layout_marginStart="24dp"
-        android:layout_marginEnd="24dp"
-        android:layout_marginBottom="16dp"
-        android:gravity="center_horizontal"
-        android:textAppearance="@style/TextAppearance.TextMedium.Secondary"
-        android:text="@string/signin_account_picker_bottom_sheet_subtitle"
-        app:leading="@dimen/text_size_medium_leading" />
+    <include layout="@layout/account_picker_bottom_sheet_header" />
 
     <View
         android:id="@+id/account_picker_horizontal_divider"