[tab-under] Add pref to turn feature off

A followup will hook this pref with a new enterprise policy to turn the
feature off.

Bug: 823700
Change-Id: I06096460a372941ba06f3bf3e9cc63b9084f82cd
Reviewed-on: https://chromium-review.googlesource.com/970729Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Commit-Queue: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544375}

chrome/browser/prefs/browser_prefs.cc

@@ -55,6 +55,7 @@
 #include "chrome/browser/task_manager/task_manager_interface.h"
 #include "chrome/browser/tracing/chrome_tracing_delegate.h"
 #include "chrome/browser/ui/blocked_content/safe_browsing_triggered_popup_blocker.h"
+#include "chrome/browser/ui/blocked_content/tab_under_navigation_throttle.h"
 #include "chrome/browser/ui/browser_ui_prefs.h"
 #include "chrome/browser/ui/navigation_correction_tab_observer.h"
 #include "chrome/browser/ui/network_profile_bubble.h"
@@ -525,6 +526,7 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   SessionStartupPref::RegisterProfilePrefs(registry);
   signin::RegisterAccountConsistencyProfilePrefs(registry);
   syncer::SyncPrefs::RegisterProfilePrefs(registry);
+  TabUnderNavigationThrottle::RegisterProfilePrefs(registry);
   TemplateURLPrepopulateData::RegisterProfilePrefs(registry);
   translate::TranslatePrefs::RegisterProfilePrefs(registry);
   UINetworkQualityEstimatorService::RegisterProfilePrefs(registry);

chrome/browser/ui/blocked_content/popup_opener_tab_helper_unittest.cc

@@ -23,12 +23,15 @@
 #include "chrome/browser/ui/blocked_content/list_item_position.h"
 #include "chrome/browser/ui/blocked_content/popup_tracker.h"
 #include "chrome/browser/ui/blocked_content/tab_under_navigation_throttle.h"
+#include "chrome/common/pref_names.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
+#include "components/prefs/pref_service.h"
 #include "components/ukm/content/source_url_recorder.h"
 #include "components/ukm/test_ukm_recorder.h"
 #include "components/ukm/ukm_source.h"
+#include "components/user_prefs/user_prefs.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/test/navigation_simulator.h"
 #include "content/public/test/test_utils.h"
@@ -729,3 +732,20 @@ TEST_F(BlockTabUnderTest, SiteEngagementNoThreshold_Blocks) {
   auto samples = histogram_tester()->GetAllSamples(kEngagementScore);
   EXPECT_LT(0, samples[0].min);
 }
+
+TEST_F(BlockTabUnderTest, ControlledByPrefs) {
+  // Turn feature off via prefs.
+  PrefService* prefs =
+      user_prefs::UserPrefs::Get(web_contents()->GetBrowserContext());
+  prefs->SetBoolean(prefs::kTabUnderProtection, false);
+  EXPECT_TRUE(NavigateAndCommitWithoutGesture(GURL("https://first.test/")));
+  SimulatePopup();
+
+  EXPECT_TRUE(NavigateAndCommitWithoutGesture(GURL("https://example.test1/")));
+  ExpectUIShown(false);
+
+  // Turn feature back on.
+  prefs->SetBoolean(prefs::kTabUnderProtection, true);
+  EXPECT_FALSE(NavigateAndCommitWithoutGesture(GURL("https://example.test2/")));
+  ExpectUIShown(true);
+}

chrome/browser/ui/blocked_content/tab_under_navigation_throttle.cc

@@ -22,6 +22,10 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/blocked_content/list_item_position.h"
 #include "chrome/browser/ui/blocked_content/popup_opener_tab_helper.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "components/prefs/pref_service.h"
+#include "components/user_prefs/user_prefs.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
@@ -105,6 +109,13 @@ void LogTabUnderAttempt(content::NavigationHandle* handle,
 const base::Feature TabUnderNavigationThrottle::kBlockTabUnders{
     "BlockTabUnders", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// static
+void TabUnderNavigationThrottle::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterBooleanPref(prefs::kTabUnderProtection,
+                                true /* default_value */);
+}
+
 // static
 std::unique_ptr<content::NavigationThrottle>
 TabUnderNavigationThrottle::MaybeCreate(content::NavigationHandle* handle) {
@@ -124,7 +135,10 @@ TabUnderNavigationThrottle::TabUnderNavigationThrottle(
                                                  0 /* default_value */)),
       off_the_record_(
           handle->GetWebContents()->GetBrowserContext()->IsOffTheRecord()),
-      block_(base::FeatureList::IsEnabled(kBlockTabUnders)),
+      block_(base::FeatureList::IsEnabled(kBlockTabUnders) &&
+             user_prefs::UserPrefs::Get(
+                 handle->GetWebContents()->GetBrowserContext())
+                 ->GetBoolean(prefs::kTabUnderProtection)),
       has_opened_popup_since_last_user_gesture_at_start_(
           HasOpenedPopupSinceLastUserGesture()) {}
 

chrome/browser/ui/blocked_content/tab_under_navigation_throttle.h

@@ -17,6 +17,10 @@ namespace content {
 class NavigationHandle;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+};
+
 constexpr char kBlockTabUnderFormatMessage[] =
     "Chrome stopped this site from navigating to %s, see "
     "https://www.chromestatus.com/feature/5675755719622656 for more details.";
@@ -61,6 +65,8 @@ class TabUnderNavigationThrottle : public content::NavigationThrottle {
     kCount
   };
 
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
   static std::unique_ptr<content::NavigationThrottle> MaybeCreate(
       content::NavigationHandle* handle);
 

chrome/common/pref_names.cc

@@ -116,6 +116,10 @@ const char kSiteEngagementLastUpdateTime[] = "profile.last_engagement_time";
 // 5: open the New Tab Page on startup.
 const char kRestoreOnStartup[] = "session.restore_on_startup";
 
+// A boolean pref to indicate whether or not Chrome should be performing
+// tab-under protection (i.e. blocking navigations it detects as tab-unders).
+const char kTabUnderProtection[] = "tab_under_protection";
+
 // The URLs to restore on startup or when the home button is pressed. The URLs
 // are only restored on startup if kRestoreOnStartup is 4.
 const char kURLsToRestoreOnStartup[] = "session.startup_urls";

chrome/common/pref_names.h

@@ -55,6 +55,7 @@ extern const char kSupervisedUserSecondCustodianProfileImageURL[];
 extern const char kSupervisedUserSecondCustodianProfileURL[];
 extern const char kSupervisedUserSharedSettings[];
 extern const char kSupervisedUserWhitelists[];
+extern const char kTabUnderProtection[];
 extern const char kURLsToRestoreOnStartup[];
 
 #if BUILDFLAG(ENABLE_RLZ)