[Android] Added check for Tab switcher on return flag

android/brave_java_sources.gni

@@ -314,6 +314,7 @@ brave_java_sources = [
   "../../brave/android/java/org/chromium/chrome/browser/sync/BraveSyncDevices.java",
   "../../brave/android/java/org/chromium/chrome/browser/sync/settings/BraveManageSyncSettings.java",
   "../../brave/android/java/org/chromium/chrome/browser/tabmodel/BraveTabCreator.java",
+  "../../brave/android/java/org/chromium/chrome/browser/tasks/BraveReturnToChromeUtil.java",
   "../../brave/android/java/org/chromium/chrome/browser/toolbar/BraveHomeButton.java",
   "../../brave/android/java/org/chromium/chrome/browser/toolbar/BraveIncognitoToggleTabLayout.java",
   "../../brave/android/java/org/chromium/chrome/browser/toolbar/BraveToolbarManager.java",

android/java/apk_for_test.flags

@@ -581,3 +581,7 @@
 -keep class org.chromium.chrome.browser.crash.BravePureJavaExceptionReporter {
     public <init>(...);
 }
+
+-keep class org.chromium.chrome.browser.tasks.ReturnToChromeUtil {
+    *** shouldShowTabSwitcher(...);
+}

android/java/org/chromium/chrome/browser/BraveFeatureUtil.java

@@ -7,9 +7,14 @@
 
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.NativeMethods;
+import org.chromium.chrome.browser.flags.CachedFlag;
+import org.chromium.chrome.browser.flags.ChromeFeatureList;
 
 @JNINamespace("chrome::android")
 public abstract class BraveFeatureUtil {
+    public static final CachedFlag sTabSwitcherOnReturn =
+            new CachedFlag(ChromeFeatureList.TAB_SWITCHER_ON_RETURN, false);
+
     public static void enableFeature(
             String featureName, boolean enabled, boolean fallbackToDefault) {
         BraveFeatureUtilJni.get().enableFeature(featureName, enabled, fallbackToDefault);

android/java/org/chromium/chrome/browser/BraveHelper.java

@@ -39,4 +39,8 @@ public static void maybeMigrateSettings() {
             BravePrefServiceBridge.getInstance().setDesktopModeEnabled(false);
         }
     }
+
+    public static void cacheNativeFeatures() {
+        BraveFeatureUtil.sTabSwitcherOnReturn.cacheFeature();
+    }
 }

android/java/org/chromium/chrome/browser/app/BraveActivity.java

@@ -78,6 +78,7 @@
 import org.chromium.chrome.browser.ApplicationLifetime;
 import org.chromium.chrome.browser.BraveAdFreeCalloutDialogFragment;
 import org.chromium.chrome.browser.BraveAdaptiveCaptchaUtils;
+import org.chromium.chrome.browser.BraveFeatureUtil;
 import org.chromium.chrome.browser.BraveHelper;
 import org.chromium.chrome.browser.BraveRelaunchUtils;
 import org.chromium.chrome.browser.BraveRewardsHelper;
@@ -758,6 +759,7 @@ public void finishNativeInitialization() {
         BraveVpnNativeWorker.getInstance().reloadPurchasedState();
 
         BraveHelper.maybeMigrateSettings();
+        BraveHelper.cacheNativeFeatures();
 
         PrefChangeRegistrar mPrefChangeRegistrar = new PrefChangeRegistrar();
         mPrefChangeRegistrar.addObserver(BravePref.SCHEDULED_CAPTCHA_ID, this);

android/java/org/chromium/chrome/browser/tasks/BraveReturnToChromeUtil.java

@@ -0,0 +1,19 @@
+/* Copyright (c) 2022 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 http://mozilla.org/MPL/2.0/. */
+
+package org.chromium.chrome.browser.tasks;
+
+import org.chromium.chrome.browser.BraveFeatureUtil;
+import org.chromium.chrome.browser.flags.ChromeFeatureList;
+
+public final class BraveReturnToChromeUtil {
+    public static boolean shouldShowTabSwitcher(final long lastBackgroundedTimeMillis) {
+        if (!BraveFeatureUtil.sTabSwitcherOnReturn.isEnabled()) {
+            return false;
+        }
+
+        return ReturnToChromeUtil.shouldShowTabSwitcher(lastBackgroundedTimeMillis);
+    }
+}

android/javatests/org/chromium/chrome/browser/BytecodeTest.java

@@ -284,6 +284,7 @@ public void testClassesExist() throws Exception {
         Assert.assertTrue(classExists("org/chromium/chrome/browser/omnibox/LocationBarMediator"));
         Assert.assertTrue(
                 classExists("org/chromium/chrome/browser/omnibox/BraveLocationBarMediator"));
+        Assert.assertTrue(classExists("org/chromium/chrome/browser/tasks/ReturnToChromeUtil"));
     }
 
     @Test
@@ -420,6 +421,8 @@ public void testMethodsExist() throws Exception {
                 "onAssistantVoiceSearchServiceChanged", false, null));
         Assert.assertTrue(methodExists("org/chromium/chrome/browser/omnibox/LocationBarMediator",
                 "shouldShowDeleteButton", false, null));
+        Assert.assertTrue(methodExists("org/chromium/chrome/browser/tasks/ReturnToChromeUtil",
+                "shouldShowTabSwitcher", true, boolean.class, long.class));
     }
 
     @Test

build/android/bytecode/BUILD.gn

@@ -54,6 +54,7 @@ java_binary("java_bytecode_rewriter") {
     "//brave/build/android/bytecode/java/org/brave/bytecode/BravePureJavaExceptionReporterClassAdapter.java",
     "//brave/build/android/bytecode/java/org/brave/bytecode/BraveQueryTileSectionClassAdapter.java",
     "//brave/build/android/bytecode/java/org/brave/bytecode/BraveReaderModeManagerClassAdapter.java",
+    "//brave/build/android/bytecode/java/org/brave/bytecode/BraveReturnToChromeUtilClassAdapter.java",
     "//brave/build/android/bytecode/java/org/brave/bytecode/BraveSearchEngineAdapterClassAdapter.java",
     "//brave/build/android/bytecode/java/org/brave/bytecode/BraveSettingsLauncherImplClassAdapter.java",
     "//brave/build/android/bytecode/java/org/brave/bytecode/BraveShareDelegateImplClassAdapter.java",

build/android/bytecode/java/org/brave/bytecode/BraveClassAdapter.java

@@ -54,6 +54,7 @@ public static ClassVisitor createAdapter(ClassVisitor chain) {
         chain = new BravePureJavaExceptionReporterClassAdapter(chain);
         chain = new BraveQueryTileSectionClassAdapter(chain);
         chain = new BraveReaderModeManagerClassAdapter(chain);
+        chain = new BraveReturnToChromeUtilClassAdapter(chain);
         chain = new BraveSearchEngineAdapterClassAdapter(chain);
         chain = new BraveSettingsLauncherImplClassAdapter(chain);
         chain = new BraveShareDelegateImplClassAdapter(chain);

build/android/bytecode/java/org/brave/bytecode/BraveReturnToChromeUtilClassAdapter.java

@@ -0,0 +1,22 @@
+/* Copyright (c) 2022 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 http://mozilla.org/MPL/2.0/. */
+
+package org.brave.bytecode;
+
+import org.objectweb.asm.ClassVisitor;
+
+public class BraveReturnToChromeUtilClassAdapter extends BraveClassVisitor {
+    static String sReturnToChromeUtilClassName =
+            "org/chromium/chrome/browser/tasks/ReturnToChromeUtil";
+    static String sBraveReturnToChromeUtilClassName =
+            "org/chromium/chrome/browser/tasks/BraveReturnToChromeUtil";
+
+    public BraveReturnToChromeUtilClassAdapter(ClassVisitor visitor) {
+        super(visitor);
+
+        changeMethodOwner(sReturnToChromeUtilClassName, "shouldShowTabSwitcher",
+                sBraveReturnToChromeUtilClassName);
+    }
+}