Fix flaky vertical tab grouping tests (#31935)

browser/misc_metrics/BUILD.gn

@@ -164,6 +164,7 @@ source_set("browser_tests") {
     "//base/test:test_support",
     "//brave/browser/misc_metrics:misc_metrics_impl",
     "//chrome/browser/profiles:profile",
+    "//chrome/browser/tab_group_sync:factories",
     "//chrome/test:test_support",
     "//components/prefs:test_support",
     "//testing/gtest",

browser/misc_metrics/vertical_tab_metrics_browsertest.cc

@@ -3,16 +3,19 @@
  * 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 "base/test/metrics/histogram_tester.h"
 #include "brave/browser/misc_metrics/vertical_tab_metrics.h"
+
+#include "base/test/metrics/histogram_tester.h"
 #include "brave/browser/ui/tabs/brave_tab_prefs.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/tab_group_sync/tab_group_sync_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/prefs/pref_service.h"
+#include "components/saved_tab_groups/public/tab_group_sync_service.h"
 #include "content/public/test/browser_test.h"
 
 namespace misc_metrics {
@@ -103,6 +106,12 @@ IN_PROC_BROWSER_TEST_F(VerticalTabMetricsTest, PinnedTabs) {
 }
 
 IN_PROC_BROWSER_TEST_F(VerticalTabMetricsTest, GroupTabs) {
+  auto* tab_groups_service =
+      tab_groups::TabGroupSyncServiceFactory::GetForProfile(
+          browser()->profile());
+  ASSERT_TRUE(tab_groups_service);
+  tab_groups_service->SetIsInitializedForTesting(true);
+
   chrome::AddTabAt(browser(), {}, -1, true);
 
   histogram_tester_.ExpectTotalCount(kVerticalGroupTabsHistogramName, 0);

browser/ui/tabs/test/BUILD.gn

@@ -18,6 +18,7 @@ source_set("browser_tests") {
     "//chrome/app:command_ids",
     "//chrome/browser",
     "//chrome/browser/profiles:profile",
+    "//chrome/browser/tab_group_sync:factories",
     "//chrome/browser/ui",
     "//chrome/browser/ui:browser_navigator_params_headers",
     "//components/prefs",

browser/ui/tabs/test/tree_tabs_browsertest.cc

@@ -8,10 +8,12 @@
 #include "brave/browser/ui/tabs/brave_tab_strip_model.h"
 #include "brave/browser/ui/tabs/features.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/tab_group_sync/tab_group_sync_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_group_model.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/prefs/pref_service.h"
+#include "components/saved_tab_groups/public/tab_group_sync_service.h"
 #include "components/tabs/public/tab_strip_collection.h"
 #include "components/tabs/public/unpinned_tab_collection.h"
 #include "content/public/browser/web_contents.h"
@@ -177,6 +179,12 @@ IN_PROC_BROWSER_TEST_F(TreeTabsBrowserTest,
 }
 
 IN_PROC_BROWSER_TEST_F(TreeTabsBrowserTest, BuildTreeTabs_WithGroupedTabs) {
+  auto* tab_groups_service =
+      tab_groups::TabGroupSyncServiceFactory::GetForProfile(
+          browser()->profile());
+  ASSERT_TRUE(tab_groups_service);
+  tab_groups_service->SetIsInitializedForTesting(true);
+
   // Add tabs to the browser.
   for (int i = 0; i < 4; ++i) {
     AddTab();
@@ -218,6 +226,12 @@ IN_PROC_BROWSER_TEST_F(TreeTabsBrowserTest, BuildTreeTabs_WithGroupedTabs) {
 }
 
 IN_PROC_BROWSER_TEST_F(TreeTabsBrowserTest, FlattenTreeTabs_WithGroupedTabs) {
+  auto* tab_groups_service =
+      tab_groups::TabGroupSyncServiceFactory::GetForProfile(
+          browser()->profile());
+  ASSERT_TRUE(tab_groups_service);
+  tab_groups_service->SetIsInitializedForTesting(true);
+
   // Add tabs and create a group.
   for (int i = 0; i < 4; ++i) {
     AddTab();

browser/ui/views/frame/vertical_tabs/vertical_tab_strip_browsertest.cc

@@ -778,6 +778,12 @@ IN_PROC_BROWSER_TEST_F(VerticalTabStripStringBrowserTest, ContextMenuString) {
 }
 
 IN_PROC_BROWSER_TEST_F(VerticalTabStripBrowserTest, PinningGroupedTab) {
+  auto* tab_groups_service =
+      tab_groups::TabGroupSyncServiceFactory::GetForProfile(
+          browser()->profile());
+  ASSERT_TRUE(tab_groups_service);
+  tab_groups_service->SetIsInitializedForTesting(true);
+
   // Regression check for https://github.com/brave/brave-browser/issues/40201
   ToggleVerticalTabStrip();