Improve licensing notice (fixes brave/brave-browser#6605)

This add a link to the license, build instructions as well as the
corresponding source code.

app/brave_generated_resources.grd

@@ -640,6 +640,11 @@ By installing this extension, you are agreeing to the Google Widevine Terms of U
       <message name="IDS_BRAVE_CRYPTO_WALLETS_SETUP" desc="Use Crypto Wallets">
         SETUP
       </message>
+      <!-- Brave's copyright statement -->
+      <message name="IDS_BRAVE_VERSION_UI_LICENSE" desc="The label below the copyright message, containing the URLs.">
+        Brave is made available to you under the <ph name="BEGIN_LINK_MPL">&lt;a target="_blank" href="$1"&gt;</ph>Mozilla Public License 2.0<ph name="END_LINK_MPL">&lt;/a&gt;</ph> (MPL) and includes <ph name="BEGIN_LINK_OSS">&lt;a target="_blank" href="$2"&gt;</ph>open source software<ph name="END_LINK_OSS">&lt;/a&gt;</ph> under a variety of other licenses.
+        You can read <ph name="BEGIN_LINK_BUILD_INSTRUCTIONS">&lt;a target="_blank" href="$3"&gt;</ph>instructions on how to download and build for yourself<ph name="END_LINK_BUILD_INSTRUCTIONS">&lt;/a&gt;</ph> the specific <ph name="BEGIN_LINK_SOURCE_CODE">&lt;a target="_blank" href="$4"&gt;</ph>source code used to create this copy<ph name="END_LINK_SOURCE_CODE">&lt;/a&gt;</ph>.
+      </message>
     </messages>
     <includes>
       <include name="IDR_BRAVE_GOOGLE_ANALYTICS_POLYFILL" file="resources/js/google_analytics_polyfill.js" type="BINDATA" />

browser/ui/BUILD.gn

@@ -66,6 +66,8 @@ source_set("ui") {
       "webui/brave_settings_ui.h",
       "webui/navigation_bar_data_provider.cc",
       "webui/navigation_bar_data_provider.h",
+      "webui/settings/brave_about_handler.cc",
+      "webui/settings/brave_about_handler.h",
       "webui/settings/brave_privacy_handler.cc",
       "webui/settings/brave_privacy_handler.h",
       "webui/settings/default_brave_shields_handler.cc",
@@ -184,7 +186,10 @@ source_set("ui") {
   }
 
   if (!is_android) {
-    deps += [ "//brave/app:brave_generated_resources_grit" ]
+    deps += [
+      "//brave/app:brave_generated_resources_grit",
+      "//brave/browser:version_info",
+    ]
   }
 
   if (enable_extensions && toolkit_views) {

browser/ui/webui/settings/brave_about_handler.cc

@@ -0,0 +1,43 @@
+/* Copyright (c) 2019 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "brave/browser/ui/webui/settings/brave_about_handler.h"
+
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "brave/browser/version_info.h"
+#include "brave/grit/brave_generated_resources.h"
+#include "chrome/browser/ui/webui/settings/about_handler.h"
+#include "chrome/common/url_constants.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace {
+
+const char kBraveBuildInstructionsUrl[] =
+    "https://github.com/brave/brave-browser/wiki";
+const char kBraveLicenseUrl[] = "https://mozilla.org/MPL/2.0/";
+const char kBraveReleaseTagPrefix[] =
+    "https://github.com/brave/brave-browser/releases/tag/v";
+
+}  // namespace
+
+namespace settings {
+
+AboutHandler* BraveAboutHandler::Create(content::WebUIDataSource* html_source,
+                                        Profile* profile) {
+  AboutHandler* handler = AboutHandler::Create(html_source, profile);
+  base::string16 license = l10n_util::GetStringFUTF16(
+      IDS_BRAVE_VERSION_UI_LICENSE, base::ASCIIToUTF16(kBraveLicenseUrl),
+      base::ASCIIToUTF16(chrome::kChromeUICreditsURL),
+      base::ASCIIToUTF16(kBraveBuildInstructionsUrl),
+      base::ASCIIToUTF16(kBraveReleaseTagPrefix) +
+          base::UTF8ToUTF16(
+              version_info::GetBraveVersionWithoutChromiumMajorVersion()));
+  html_source->AddString("aboutProductLicense", license);
+  return handler;
+}
+
+}  // namespace settings

browser/ui/webui/settings/brave_about_handler.h

@@ -0,0 +1,27 @@
+/* Copyright (c) 2019 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef BRAVE_BROWSER_UI_WEBUI_SETTINGS_BRAVE_ABOUT_HANDLER_H_
+#define BRAVE_BROWSER_UI_WEBUI_SETTINGS_BRAVE_ABOUT_HANDLER_H_
+
+class Profile;
+
+namespace content {
+class WebUIDataSource;
+}
+
+namespace settings {
+
+class AboutHandler;
+
+class BraveAboutHandler {
+ public:
+  static AboutHandler* Create(content::WebUIDataSource* html_source,
+                              Profile* profile);
+};
+
+}  // namespace settings
+
+#endif  // BRAVE_BROWSER_UI_WEBUI_SETTINGS_BRAVE_ABOUT_HANDLER_H_

chromium_src/chrome/browser/ui/webui/settings/settings_ui.cc

@@ -0,0 +1,11 @@
+/* Copyright (c) 2019 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "brave/browser/ui/webui/settings/brave_about_handler.h"
+#include "chrome/browser/ui/webui/settings/about_handler.h"
+
+#define AboutHandler BraveAboutHandler
+#include "../../../../../../../chrome/browser/ui/webui/settings/settings_ui.cc"
+#undef AboutHandler