[Start Surface] Move logic to show Start Surface for NTP to Tabcreator

TabCreator:
-selects TabModel and shows StartSurface HomePage instead of launching NTP if applicable.

ChromeTabbedActivity:
-restores active tab if StartSurface is shown on start and not incognito.
-InternalIntentDelegate and shouldShowTabSwitcherOnStart updated

StartSurfaceMediator:
-trigger tabswitcher update when active tab is restored to load tab carousel

Change-Id: I45809c1cd604bd035c008375c1b68a2aba8ba715
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032038
Commit-Queue: Mia Glaese <glamia@chromium.org>
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743594}

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceMediator.java

@@ -204,6 +204,16 @@ class StartSurfaceMediator
                             setTabCarouselVisibility(true);
                         }
                     }
+
+                    @Override
+                    public void restoreCompleted() {
+                        if (!(mPropertyModel.get(IS_SHOWING_OVERVIEW)
+                                    && mOverviewModeState == OverviewModeState.SHOWN_HOMEPAGE)) {
+                            return;
+                        }
+                        setTabCarouselVisibility(
+                                mTabModelSelector.getModel(false).getCount() > 0 && !mIsIncognito);
+                    }
                 };
 
                 mFullScreenListener = new ChromeFullscreenManager.FullscreenListener() {

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java

@@ -668,16 +668,10 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
                 }
             };
             OnClickListener newTabClickHandler = v -> {
-                // If Start Surface should be shown as the home page, show the start surface home
-                // page.
-                if (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()) {
-                    showOverview(OverviewModeState.SHOWING_HOMEPAGE);
-                } else {
-                    getTabModelSelector().getModel(false).commitAllTabClosures();
-                    // This assumes that the keyboard can not be seen at the same time as the
-                    // newtab button on the toolbar.
-                    getCurrentTabCreator().launchNTP();
-                }
+                getTabModelSelector().getModel(false).commitAllTabClosures();
+                // This assumes that the keyboard can not be seen at the same time as the
+                // newtab button on the toolbar.
+                getCurrentTabCreator().launchNTP();
                 mLocaleManager.showSearchEnginePromoIfNeeded(ChromeTabbedActivity.this, null);
                 if (getTabModelSelector().isIncognitoSelected()) {
                     RecordUserAction.record("MobileToolbarStackViewNewIncognitoTab");
@@ -697,7 +691,6 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
             Supplier<Boolean> showStartSurfaceSupplier = () -> {
                 if (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()
                         && !isTablet()) {
-                    assert ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage();
                     showOverview(OverviewModeState.SHOWING_HOMEPAGE);
                     return true;
                 }
@@ -988,7 +981,6 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
                         TAB_COUNT_ON_RETURN, getCurrentTabModel().getCount());
             }
             if (CachedFeatureFlags.isGridTabSwitcherEnabled() && !isTablet()) {
-                assert !getCurrentTabModel().isIncognito();
                 mStartSurface.getController().enableRecordingFirstMeaningfulPaint(
                         getOnCreateTimestampMs());
             }
@@ -1006,12 +998,18 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
     }
 
     private boolean shouldShowTabSwitcherOnStart() {
-        if (!isMainIntentFromLauncher(getIntent())) return false;
+        if (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()) {
+            String intentUrl = IntentHandler.getUrlFromIntent(getIntent());
+            if (NewTabPage.isNTPUrl(intentUrl)
+                    || (isMainIntentFromLauncher(getIntent())
+                            && (getTabModelSelector().getTotalTabCount() <= 0))) {
+                return true;
+            }
+        }
 
         long lastBackgroundedTimeMillis = mInactivityTracker.getLastBackgroundedTimeMs();
-        return (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()
-                       && getTabModelSelector().getTotalTabCount() <= 0)
-                || ReturnToChromeExperimentsUtil.shouldShowTabSwitcher(lastBackgroundedTimeMillis);
+        return isMainIntentFromLauncher(getIntent())
+                && ReturnToChromeExperimentsUtil.shouldShowTabSwitcher(lastBackgroundedTimeMillis);
     }
 
     private boolean isMainIntentFromLauncher(Intent intent) {
@@ -1100,7 +1098,9 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
             // We always need to try to restore tabs. The set of tabs might be empty, but at least
             // it will trigger the notification that tab restore is complete which is needed by
             // other parts of Chrome such as sync.
-            boolean activeTabBeingRestored = !mIntentWithEffect;
+            boolean activeTabBeingRestored = !mIntentWithEffect
+                    || (shouldShowTabSwitcherOnStart()
+                            && !mTabModelSelectorImpl.isIncognitoSelected());
 
             mMainIntentMetrics.setIgnoreEvents(true);
             mTabModelSelectorImpl.restoreTabs(activeTabBeingRestored);
@@ -1375,7 +1375,8 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
                     focus ? LocationBar.OmniboxFocusReason.LAUNCH_NEW_INCOGNITO_TAB
                           : LocationBar.OmniboxFocusReason.UNFOCUS);
 
-            if (tabModel.getCount() > 0 && isInOverviewMode() && !isTablet()) {
+            if (tabModel.getCount() > 0 && isInOverviewMode() && !isTablet()
+                    && !shouldShowTabSwitcherOnStart()) {
                 mOverviewModeController.hideOverview(true);
             }
         }
@@ -1568,10 +1569,21 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
             return new TabbedModeTabDelegateFactory(
                     this, getAppBrowserControlsVisibilityDelegate(), getShareDelegateSupplier());
         };
+
+        ChromeTabCreator.OverviewNTPCreator overviewNTPCreator = null;
+
+        if (CachedFeatureFlags.isStartSurfaceEnabled()) {
+            overviewNTPCreator = new ChromeTabCreator.OverviewNTPCreator() {
+                @Override
+                public boolean handleCreateNTPIfNeeded(boolean isNTP, boolean incognito) {
+                    return showStartSurfaceHomeForNTP(isNTP, incognito);
+                }
+            };
+        }
         return Pair.create(new ChromeTabCreator(this, getWindowAndroid(), getStartupTabPreloader(),
-                                   tabDelegateFactorySupplier, false),
+                                   tabDelegateFactorySupplier, false, overviewNTPCreator),
                 new ChromeTabCreator(this, getWindowAndroid(), getStartupTabPreloader(),
-                        tabDelegateFactorySupplier, true));
+                        tabDelegateFactorySupplier, true, overviewNTPCreator));
     }
 
     @Override
@@ -1623,13 +1635,7 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
             reportNewTabShortcutUsed(false);
             if (fromMenu) RecordUserAction.record("MobileMenuNewTab.AppMenu");
 
-            // If Start Surface should be shown as the home page, show the start surface home page.
-            if (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()) {
-                getTabModelSelector().selectModel(false);
-                showOverview(OverviewModeState.SHOWING_HOMEPAGE);
-            } else {
-                getTabCreator(false).launchNTP();
-            }
+            getTabCreator(false).launchNTP();
 
             mLocaleManager.showSearchEnginePromoIfNeeded(this, null);
         } else if (id == R.id.new_incognito_tab_menu_id) {
@@ -1641,15 +1647,7 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
                 RecordUserAction.record("MobileNewTabOpened");
                 reportNewTabShortcutUsed(true);
                 if (fromMenu) RecordUserAction.record("MobileMenuNewIncognitoTab.AppMenu");
-
-                // If Start Surface should be shown as the home page, show the start surface home
-                // page.
-                if (ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()) {
-                    getTabModelSelector().selectModel(true);
-                    showOverview(OverviewModeState.SHOWING_HOMEPAGE);
-                } else {
-                    getTabCreator(true).launchNTP();
-                }
+                getTabCreator(true).launchNTP();
             }
         } else if (id == R.id.all_bookmarks_menu_id) {
             // Note that 'currentTab' could be null in overview mode when start surface is
@@ -1969,6 +1967,16 @@ public class ChromeTabbedActivity extends ChromeActivity implements Accessibilit
         }
     }
 
+    private boolean showStartSurfaceHomeForNTP(boolean isNTP, boolean incognito) {
+        if (isNTP && ReturnToChromeExperimentsUtil.shouldShowStartSurfaceAsTheHomePage()
+                && !isTablet()) {
+            getTabModelSelector().selectModel(incognito);
+            showOverview(OverviewModeState.SHOWING_HOMEPAGE);
+            return true;
+        }
+        return false;
+    }
+
     private void updateAccessibilityState(boolean enabled) {
         Tab currentTab = getActivityTab();
         WebContents webContents = currentTab != null ? currentTab.getWebContents() : null;

chrome/android/java/src/org/chromium/chrome/browser/customtabs/content/CustomTabActivityTabFactory.java

@@ -87,7 +87,7 @@ public class CustomTabActivityTabFactory {
 
     private ChromeTabCreator createTabCreator(boolean incognito) {
         return new ChromeTabCreator(mActivity, mActivityWindowAndroid.get(), mStartupTabPreloader,
-                mCustomTabDelegateFactory::get, incognito);
+                mCustomTabDelegateFactory::get, incognito, null);
     }
 
     /** Creates a new tab for a Custom Tab activity */

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/ChromeTabCreator.java

@@ -17,6 +17,7 @@ import org.chromium.chrome.browser.IntentHandler;
 import org.chromium.chrome.browser.ServiceTabLauncher;
 import org.chromium.chrome.browser.init.StartupTabPreloader;
 import org.chromium.chrome.browser.net.spdyproxy.DataReductionProxySettings;
+import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabAssociatedApp;
 import org.chromium.chrome.browser.tab.TabBuilder;
@@ -40,6 +41,16 @@ import org.chromium.url.GURL;
  * This class creates various kinds of new tabs and adds them to the right {@link TabModel}.
  */
 public class ChromeTabCreator extends TabCreatorManager.TabCreator {
+    /**Interface to handle showing overview instead of NTP if needed. */
+    public interface OverviewNTPCreator {
+        /**
+         * Handles showing the StartSurface instead of the NTP if needed.
+         * @param isNTPUrl Whether tab with NTP should be created.
+         * @param isIncognito Whether tab is created in incognito.
+         * @return Whether NTP creation was handled.
+         */
+        boolean handleCreateNTPIfNeeded(boolean isNTP, boolean incognito);
+    }
 
     private final ChromeActivity mActivity;
     private final StartupTabPreloader mStartupTabPreloader;
@@ -49,15 +60,19 @@ public class ChromeTabCreator extends TabCreatorManager.TabCreator {
     private TabModel mTabModel;
     private TabModelOrderController mOrderController;
     private Supplier<TabDelegateFactory> mTabDelegateFactorySupplier;
+    @Nullable
+    private OverviewNTPCreator mOverviewNTPCreator;
 
     public ChromeTabCreator(ChromeActivity activity, WindowAndroid nativeWindow,
             StartupTabPreloader startupTabPreloader,
-            Supplier<TabDelegateFactory> tabDelegateFactory, boolean incognito) {
+            Supplier<TabDelegateFactory> tabDelegateFactory, boolean incognito,
+            OverviewNTPCreator overviewNTPCreator) {
         mActivity = activity;
         mStartupTabPreloader = startupTabPreloader;
         mNativeWindow = nativeWindow;
         mTabDelegateFactorySupplier = tabDelegateFactory;
         mIncognito = incognito;
+        mOverviewNTPCreator = overviewNTPCreator;
     }
 
     @Override
@@ -106,6 +121,11 @@ public class ChromeTabCreator extends TabCreatorManager.TabCreator {
      */
     private Tab createNewTab(LoadUrlParams loadUrlParams, @TabLaunchType int type, Tab parent,
             int position, Intent intent) {
+        if (mOverviewNTPCreator != null
+                && mOverviewNTPCreator.handleCreateNTPIfNeeded(
+                        NewTabPage.isNTPUrl(loadUrlParams.getUrl()), mIncognito)) {
+            return null;
+        }
         try {
             TraceEvent.begin("ChromeTabCreator.createNewTab");
             int parentId = parent != null ? parent.getId() : Tab.INVALID_TAB_ID;

chrome/android/javatests/src/org/chromium/chrome/browser/init/StartupTabPreloaderUnitTest.java

@@ -171,7 +171,7 @@ public class StartupTabPreloaderUnitTest {
         @Override
         public TabCreatorManager.TabCreator getTabCreator(boolean incognito) {
             Assert.assertFalse(incognito);
-            return new ChromeTabCreator(null, null, null, null, false);
+            return new ChromeTabCreator(null, null, null, null, false, null);
         }
     }