From: csagan5 <32685696+csagan5@users.noreply.github.com>
Date: Sat, 20 Nov 2021 15:36:54 +0000
Subject: Add option to use home page as NTP

And allow use about:blank as default homepage

License: GPL-3.0-only - https://spdx.org/licenses/GPL-3.0-only.html
---
 .../tab_management/TabGridDialogMediator.java    |  9 ++++++++-
 .../tasks/tab_management/TabGroupUiMediator.java |  8 +++++++-
 .../java/res/xml/homepage_preferences.xml        |  5 +++++
 .../chrome/browser/homepage/HomepageManager.java | 16 ++++++++++++++++
 .../homepage/settings/HomepageSettings.java      | 12 ++++++++++++
 .../chrome/browser/metrics/LaunchMetrics.java    |  1 -
 .../browser/tabmodel/ChromeTabCreator.java       |  8 ++++++++
 .../preferences/ChromePreferenceKeys.java        |  1 +
 .../preferences/LegacyChromePreferenceKeys.java  |  1 +
 .../android/strings/android_chrome_strings.grd   |  3 +++
 chrome/browser/ui/browser_ui_prefs.cc            |  2 ++
 chrome/common/pref_names.h                       |  4 ++++
 12 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridDialogMediator.java b/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridDialogMediator.java
--- a/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridDialogMediator.java
+++ b/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridDialogMediator.java
@@ -18,6 +18,7 @@ import org.chromium.base.Callback;
 import org.chromium.base.ResettersForTesting;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.base.supplier.Supplier;
+import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabCreationState;
 import org.chromium.chrome.browser.tab.TabLaunchType;
@@ -44,6 +45,7 @@ import org.chromium.ui.KeyboardVisibilityDelegate;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.modelutil.PropertyModel;
 import org.chromium.ui.text.EmptyTextWatcher;
+import org.chromium.url.GURL;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -564,9 +566,14 @@ public class TabGridDialogMediator
 
             assert relatedTabs.size() > 0;
 
+            String url = UrlConstants.NTP_URL;
+            if (HomepageManager.getInstance().getPrefNTPIsHomepageEnabled()) {
+                GURL gurl = HomepageManager.getInstance().getHomepageGurl();
+                url = gurl != null ? gurl.getSpec() : url;
+            }
             Tab parentTabToAttach = relatedTabs.get(relatedTabs.size() - 1);
             mTabCreatorManager.getTabCreator(currentTab.isIncognito())
-                    .createNewTab(new LoadUrlParams(UrlConstants.NTP_URL),
+                    .createNewTab(new LoadUrlParams(url),
                             TabLaunchType.FROM_TAB_GROUP_UI, parentTabToAttach);
             RecordUserAction.record("MobileNewTabOpened." + mComponentName);
         };
diff --git a/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGroupUiMediator.java b/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGroupUiMediator.java
--- a/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGroupUiMediator.java
+++ b/chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGroupUiMediator.java
@@ -17,6 +17,7 @@ import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.base.supplier.ObservableSupplier;
 import org.chromium.base.supplier.ObservableSupplierImpl;
 import org.chromium.base.supplier.OneshotSupplier;
+import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.layouts.LayoutStateProvider;
 import org.chromium.chrome.browser.layouts.LayoutStateProvider.LayoutStateObserver;
 import org.chromium.chrome.browser.layouts.LayoutType;
@@ -345,8 +346,13 @@ public class TabGroupUiMediator implements BackPressHandler {
             assert relatedTabs.size() > 0;
 
             parentTabToAttach = relatedTabs.get(relatedTabs.size() - 1);
+            String url = UrlConstants.NTP_URL;
+            if (HomepageManager.getInstance().getPrefNTPIsHomepageEnabled()) {
+                GURL gurl = HomepageManager.getInstance().getHomepageGurl();
+                url = gurl != null ? gurl.getSpec() : url;
+            }
             mTabCreatorManager.getTabCreator(currentTab.isIncognito())
-                    .createNewTab(new LoadUrlParams(UrlConstants.NTP_URL),
+                    .createNewTab(new LoadUrlParams(url),
                             TabLaunchType.FROM_TAB_GROUP_UI, parentTabToAttach);
             RecordUserAction.record("MobileNewTabOpened." + TabGroupUiCoordinator.COMPONENT_NAME);
         };
diff --git a/chrome/android/java/res/xml/homepage_preferences.xml b/chrome/android/java/res/xml/homepage_preferences.xml
--- a/chrome/android/java/res/xml/homepage_preferences.xml
+++ b/chrome/android/java/res/xml/homepage_preferences.xml
@@ -14,6 +14,11 @@ found in the LICENSE file.
         android:summaryOn="@string/text_on"
         android:summaryOff="@string/text_off" />
 
+    <org.chromium.components.browser_ui.settings.ChromeSwitchPreference
+        android:key="ntp_is_homepage_switch"
+        android:summaryOn="@string/options_ntp_is_homepage_label"
+        android:summaryOff="@string/options_ntp_is_homepage_label" />
+
     <org.chromium.chrome.browser.homepage.settings.RadioButtonGroupHomepagePreference
         android:key="homepage_radio_group"
         android:selectable="false"
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/homepage/HomepageManager.java b/chrome/android/java/src/org/chromium/chrome/browser/homepage/HomepageManager.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/homepage/HomepageManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/homepage/HomepageManager.java
@@ -238,6 +238,22 @@ public class HomepageManager implements HomepagePolicyManager.HomepagePolicyStat
         notifyHomepageUpdated();
     }
 
+    /**
+     * Returns the user preference for whether the New Tab Page is the homepage or not.
+     *
+     */
+    public boolean getPrefNTPIsHomepageEnabled() {
+        return mSharedPreferencesManager.readBoolean(ChromePreferenceKeys.HOMEPAGE_NTP_IS_HOMEPAGE, false);
+    }
+
+    /**
+     * Sets the user preference for whether the new tab page is the homepage or not.
+     */
+    public void setPrefNTPIsHomepageEnabled(boolean enabled) {
+        mSharedPreferencesManager.writeBoolean(ChromePreferenceKeys.HOMEPAGE_NTP_IS_HOMEPAGE, enabled);
+        notifyHomepageUpdated();
+    }
+
     /**
      * @return User specified homepage custom GURL.
      */
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/homepage/settings/HomepageSettings.java b/chrome/android/java/src/org/chromium/chrome/browser/homepage/settings/HomepageSettings.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/homepage/settings/HomepageSettings.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/homepage/settings/HomepageSettings.java
@@ -22,6 +22,7 @@ import org.chromium.components.browser_ui.settings.SettingsUtils;
 import org.chromium.components.embedder_support.util.UrlUtilities;
 import org.chromium.components.url_formatter.UrlFormatter;
 import org.chromium.url.GURL;
+import org.chromium.components.embedder_support.util.UrlConstants;
 
 /**
  * Fragment that allows the user to configure homepage related preferences.
@@ -32,6 +33,8 @@ public class HomepageSettings extends ChromeBaseSettingsFragment {
     @VisibleForTesting
     public static final String PREF_HOMEPAGE_RADIO_GROUP = "homepage_radio_group";
 
+    private static final String PREF_NTP_HOMEPAGE_SWITCH = "ntp_is_homepage_switch";
+
     private HomepageManager mHomepageManager;
     private RadioButtonGroupHomepagePreference mRadioButtons;
 
@@ -65,6 +68,15 @@ public class HomepageSettings extends ChromeBaseSettingsFragment {
         });
         mRadioButtons.setupPreferenceValues(createPreferenceValuesForRadioGroup());
 
+        ChromeSwitchPreference mNTPIsHomepageSwitch =
+                (ChromeSwitchPreference) findPreference(PREF_NTP_HOMEPAGE_SWITCH);
+        boolean isHomepageNTPEnabled = mHomepageManager.getPrefNTPIsHomepageEnabled();
+        mNTPIsHomepageSwitch.setChecked(isHomepageNTPEnabled);
+        mNTPIsHomepageSwitch.setOnPreferenceChangeListener((preference, newValue) -> {
+            mHomepageManager.setPrefNTPIsHomepageEnabled((boolean) newValue);
+            return true;
+        });
+
         RecordUserAction.record("Settings.Homepage.Opened");
     }
 
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java b/chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/metrics/LaunchMetrics.java
@@ -103,7 +103,6 @@ public class LaunchMetrics {
     public static void recordHomePageLaunchMetrics(
             boolean showHomeButton, boolean homepageIsNtp, GURL homepageGurl) {
         if (homepageGurl.isEmpty()) {
-            assert !showHomeButton : "Homepage should be disabled for an empty GURL";
         }
         LaunchMetricsJni.get().recordHomePageLaunchMetrics(
                 showHomeButton, homepageIsNtp, homepageGurl);
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/ChromeTabCreator.java b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/ChromeTabCreator.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/ChromeTabCreator.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/ChromeTabCreator.java
@@ -27,6 +27,7 @@ import org.chromium.chrome.browser.compositor.CompositorViewHolder;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.incognito.IncognitoUtils;
 import org.chromium.chrome.browser.new_tab_url.DseNewTabUrlManager;
+import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.ntp.NewTabPageLaunchOrigin;
 import org.chromium.chrome.browser.ntp.NewTabPageUtils;
 import org.chromium.chrome.browser.prefetch.settings.PreloadPagesSettingsBridge;
@@ -502,6 +503,13 @@ public class ChromeTabCreator extends TabCreator {
      * @return the created tab.
      */
     public Tab launchUrl(String url, @TabLaunchType int type, Intent intent, long intentTimestamp) {
+        if (!mIncognito && url.equals(UrlConstants.NTP_URL)) {
+            if (HomepageManager.getInstance().getPrefNTPIsHomepageEnabled()) {
+                GURL gurl = HomepageManager.getInstance().getHomepageGurl();
+                url = gurl != null ? gurl.getSpec() : url;
+            }
+        }
+
         LoadUrlParams loadUrlParams = new LoadUrlParams(url);
         loadUrlParams.setIntentReceivedTimestamp(intentTimestamp);
         return createNewTab(loadUrlParams, type, null, intent);
diff --git a/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java b/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java
--- a/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java
+++ b/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java
@@ -367,6 +367,7 @@ public final class ChromePreferenceKeys {
     public static final String HOMEPAGE_USE_CHROME_NTP = "Chrome.Homepage.UseNTP";
     public static final String HOMEPAGE_USE_DEFAULT_URI = "homepage_partner_enabled";
 
+    public static final String HOMEPAGE_NTP_IS_HOMEPAGE = "newtabpage_is_homepage";
     /**
      * Key used to save homepage location set by enterprise policy
      */
diff --git a/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/LegacyChromePreferenceKeys.java b/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/LegacyChromePreferenceKeys.java
--- a/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/LegacyChromePreferenceKeys.java
+++ b/chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/LegacyChromePreferenceKeys.java
@@ -68,6 +68,7 @@ public class LegacyChromePreferenceKeys {
                 ChromePreferenceKeys.HISTORY_SHOW_HISTORY_INFO,
                 ChromePreferenceKeys.HOMEPAGE_ENABLED,
                 ChromePreferenceKeys.HOMEPAGE_USE_DEFAULT_URI,
+                ChromePreferenceKeys.HOMEPAGE_NTP_IS_HOMEPAGE,
                 ChromePreferenceKeys.INCOGNITO_SHORTCUT_ADDED,
                 ChromePreferenceKeys.LATEST_UNSUPPORTED_VERSION,
                 ChromePreferenceKeys.LOCALE_MANAGER_AUTO_SWITCH,
diff --git a/chrome/browser/ui/android/strings/android_chrome_strings.grd b/chrome/browser/ui/android/strings/android_chrome_strings.grd
--- a/chrome/browser/ui/android/strings/android_chrome_strings.grd
+++ b/chrome/browser/ui/android/strings/android_chrome_strings.grd
@@ -1540,6 +1540,9 @@ Your Google account may have other forms of browsing history like searches and a
       <message name="IDS_CLEAR_BROWSING_DATA_TAB_PERIOD_HOUR" desc="The option to delete browsing data from the last hour.">
         Last hour
       </message>
+      <message name="IDS_OPTIONS_NTP_IS_HOMEPAGE_LABEL" desc="The label for switch that allows the user to toggle whether opening a new tab leads to the new tab page or the home page.">
+        Use for new tabs
+      </message>
       <message name="IDS_CLEAR_BROWSING_DATA_TAB_PERIOD_24_HOURS" desc="The option to delete browsing data from the last 24 hours.">
         Last 24 hours
       </message>
diff --git a/chrome/browser/ui/browser_ui_prefs.cc b/chrome/browser/ui/browser_ui_prefs.cc
--- a/chrome/browser/ui/browser_ui_prefs.cc
+++ b/chrome/browser/ui/browser_ui_prefs.cc
@@ -70,6 +70,8 @@ void RegisterBrowserUserPrefs(user_prefs::PrefRegistrySyncable* registry) {
                                 GetHomeButtonAndHomePageIsNewTabPageFlags());
   registry->RegisterBooleanPref(prefs::kShowHomeButton, false,
                                 GetHomeButtonAndHomePageIsNewTabPageFlags());
+  registry->RegisterBooleanPref(prefs::kNewTabPageIsHomePage, false,
+                                GetHomeButtonAndHomePageIsNewTabPageFlags());
 
   registry->RegisterInt64Pref(prefs::kDefaultBrowserLastDeclined, 0);
   bool reset_check_default = false;
diff --git a/chrome/common/pref_names.h b/chrome/common/pref_names.h
--- a/chrome/common/pref_names.h
+++ b/chrome/common/pref_names.h
@@ -1283,6 +1283,10 @@ inline constexpr char kUsedPolicyCertificates[] =
 // visible on the toolbar.
 inline constexpr char kShowHomeButton[] = "browser.show_home_button";
 
+// A boolean specifying whether opening a new tab should open the Home page
+// instead of the New Tab page.
+inline constexpr char kNewTabPageIsHomePage[] = "newtabpage_is_homepage";
+
 // Boolean pref to define the default setting for "block offensive words".
 // The old key value is kept to avoid unnecessary migration code.
 inline constexpr char kSpeechRecognitionFilterProfanities[] =
--
2.25.1