[signin] Add back button that calls the function "NavigateToPreviousRoute"

Bug: 1105865
Change-Id: I6a2b6ef0ec3e73511be20be190f74de64a5a8b49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302619Reviewed-by: David Roger <droger@chromium.org>
Reviewed-by: Monica Basta <msalama@chromium.org>
Commit-Queue: Diana Zagidullina <dizg@google.com>
Cr-Commit-Position: refs/heads/master@{#790763}

chrome/app/profiles_strings.grdp

@@ -661,4 +661,11 @@
       Don't see your name?
     </message>
   </if>
+
+  <!-- Profile Picker -->
+  <if expr="not chromeos and not is_android">
+    <message name="IDS_PROFILE_PICKER_BACK_BUTTON_LABEL" desc="Label for a button that navigates user to the previous page">
+      Back
+    </message>
+  </if>
 </grit-part>

chrome/app/profiles_strings_grdp/IDS_PROFILE_PICKER_BACK_BUTTON_LABEL.png.sha1

+d7bdadefb05b21f0fc4ed80ce2a7c18a7fd5416e
\ No newline at end of file

chrome/browser/resources/signin/profile_picker/navigation_behavior.js

@@ -88,6 +88,13 @@ export function navigateTo(route) {
   notifyObservers();
 }
 
+/**
+ * Navigates to the previous route.
+ */
+export function navigateToPreviousRoute() {
+  // TODO(crbug.com/1063856): Add implementation.
+}
+
 /** @polymerBehavior */
 export const NavigationBehavior = {
   /** @override */
@@ -111,4 +118,4 @@ export const NavigationBehavior = {
    * @param {string} step
    */
   onRouteChange: function(route, step) {},
-};
+};
\ No newline at end of file

chrome/browser/resources/signin/profile_picker/profile_creation_flow/BUILD.gn

@@ -13,6 +13,7 @@ js_type_check("closure_compile") {
 js_library("profile_type_choice") {
   deps = [
     "//third_party/polymer/v3_0/components-chromium/polymer:polymer_bundled",
+    "//ui/webui/resources/cr_elements/cr_icon_button:cr_icon_button.m",
   ]
 }
 

chrome/browser/resources/signin/profile_picker/profile_creation_flow/profile_type_choice.html

-<div> Profile type choice </div>
+<style include="cr-icons"></style>
+
+<cr-icon-button class="icon-arrow-back" id="backButton"
+    on-click="onTapBack_" aria-label="$i18n{backButtonLabel}">
+</cr-icon-button>

chrome/browser/resources/signin/profile_picker/profile_creation_flow/profile_type_choice.js

@@ -2,10 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'chrome://resources/cr_elements/cr_icon_button/cr_icon_button.m.js';
+import 'chrome://resources/cr_elements/cr_icons_css.m.js';
+
 import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
+import {navigateToPreviousRoute} from '../navigation_behavior.js';
 
 Polymer({
   is: 'profile-type-choice',
 
   _template: html`{__html_template__}`,
+
+  /** @private */
+  onTapBack_() {
+    navigateToPreviousRoute();
+  },
+
 });

chrome/browser/ui/webui/signin/profile_picker_ui.cc

@@ -9,6 +9,7 @@
 #include "chrome/browser/ui/webui/webui_util.h"
 #include "chrome/common/webui_url_constants.h"
 #include "chrome/grit/chromium_strings.h"
+#include "chrome/grit/generated_resources.h"
 #include "chrome/grit/profile_picker_resources.h"
 #include "chrome/grit/profile_picker_resources_map.h"
 #include "content/public/browser/web_ui_data_source.h"
@@ -20,6 +21,7 @@ void AddStrings(content::WebUIDataSource* html_source) {
   static constexpr webui::LocalizedString kLocalizedStrings[] = {
       {"mainViewTitle", IDS_PROFILE_PICKER_MAIN_VIEW_TITLE},
       {"mainViewSubtitle", IDS_PROFILE_PICKER_MAIN_VIEW_SUBTITLE},
+      {"backButtonLabel", IDS_PROFILE_PICKER_BACK_BUTTON_LABEL},
   };
   AddLocalizedStringsBulk(html_source, kLocalizedStrings);
 }