Modify Physical Web auto-optin behavior on Chrome for iOS

ios/chrome/browser/physical_web/start_physical_web_discovery.mm

Index: ios/chrome/browser/physical_web/start_physical_web_discovery.mm
diff --git a/ios/chrome/browser/physical_web/start_physical_web_discovery.mm b/ios/chrome/browser/physical_web/start_physical_web_discovery.mm
index e1b9502f4d8cc56e01ed7dbdf06d8108e2fde45f..a61a7652105be59e3e7dba528aabce5d29c9aede 100644
--- a/ios/chrome/browser/physical_web/start_physical_web_discovery.mm
+++ b/ios/chrome/browser/physical_web/start_physical_web_discovery.mm
@@ -7,15 +7,19 @@
 #import <CoreLocation/CoreLocation.h>
 
 #include "components/physical_web/data_source/physical_web_data_source.h"
+#include "components/search_engines/search_terms_data.h"
+#include "components/search_engines/template_url_service.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #import "ios/chrome/browser/experimental_flags.h"
 #import "ios/chrome/browser/geolocation/omnibox_geolocation_config.h"
 #include "ios/chrome/browser/physical_web/physical_web_constants.h"
 #include "ios/chrome/browser/pref_names.h"
+#include "ios/chrome/browser/search_engines/template_url_service_factory.h"
 #include "url/gurl.h"
 
-void StartPhysicalWebDiscovery(PrefService* pref_service, bool is_incognito) {
+void StartPhysicalWebDiscovery(PrefService* pref_service,
+                               ios::ChromeBrowserState* browser_state) {
   // Do not scan if the Physical Web feature is disabled by a command line flag
   // or Chrome Variations experiment.
   if (!experimental_flags::IsPhysicalWebEnabled()) {
@@ -28,6 +32,10 @@ void StartPhysicalWebDiscovery(PrefService* pref_service, bool is_incognito) {
   int preference_state =
       pref_service->GetInteger(prefs::kIosPhysicalWebEnabled);
   if (preference_state == physical_web::kPhysicalWebOnboarding) {
+    // Check whether the user is in Incognito mode. Physical Web will only be
+    // auto-enabled if the user is not in Incognito.
+    bool is_incognito = browser_state->IsOffTheRecord();
+
     // Check that Location Services is enabled.
     bool location_services_enabled =
         [CLLocationManager locationServicesEnabled];
@@ -43,13 +51,22 @@ void StartPhysicalWebDiscovery(PrefService* pref_service, bool is_incognito) {
     bool geolocation_eligible = [[OmniboxGeolocationConfig sharedInstance]
         URLHasEligibleDomain:GURL("https://www.google.com")];
 
-    if (!is_incognito && location_services_enabled && location_authorized &&
-        geolocation_eligible) {
-      pref_service->SetInteger(prefs::kIosPhysicalWebEnabled,
-                               physical_web::kPhysicalWebOn);
-      preference_state =
-          pref_service->GetInteger(prefs::kIosPhysicalWebEnabled);
-    }
+    // Check that Google Search is configured as the default search engine.
+    const TemplateURL* default_search_provider =
+        ios::TemplateURLServiceFactory::GetForBrowserState(browser_state)
+            ->GetDefaultSearchProvider();
+    bool google_search_enabled =
+        default_search_provider->IsGoogleSearchURLWithReplaceableKeyword(
+            SearchTermsData());
+
+    bool auto_enable = !is_incognito && location_services_enabled &&
+                       location_authorized && geolocation_eligible &&
+                       google_search_enabled;
+
+    pref_service->SetInteger(prefs::kIosPhysicalWebEnabled,
+                             auto_enable ? physical_web::kPhysicalWebOn
+                                         : physical_web::kPhysicalWebOff);
+    preference_state = pref_service->GetInteger(prefs::kIosPhysicalWebEnabled);
   }
 
   // Scan only if the feature is enabled.
@@ -60,7 +77,3 @@ void StartPhysicalWebDiscovery(PrefService* pref_service, bool is_incognito) {
   }
 }
 
-void StartPhysicalWebDiscovery(PrefService* pref_service,
-                               ios::ChromeBrowserState* browser_state) {
-  StartPhysicalWebDiscovery(pref_service, browser_state->IsOffTheRecord());
-}