Change debounce behavior to never debounce to same eTLD+1 (#15392)

browser/debounce/debounce_browsertest.cc

@@ -230,7 +230,8 @@ IN_PROC_BROWSER_TEST_F(DebounceBrowserTest, QuadRedirect) {
 }
 
 // Test a redirect chain that bounces from a tracker to a final URL in the
-// tracker's domain.
+// tracker's domain. This should NOT be debounced, because the tracker and
+// the final URL share an eTLD+1.
 IN_PROC_BROWSER_TEST_F(DebounceBrowserTest, SameSiteTracker) {
   ASSERT_TRUE(InstallMockExtension());
   GURL final_url = embedded_test_server()->GetURL("z.com", "/");
@@ -238,7 +239,7 @@ IN_PROC_BROWSER_TEST_F(DebounceBrowserTest, SameSiteTracker) {
       embedded_test_server()->GetURL("tracker.z.com", "/"), final_url);
   GURL start_url = add_redirect_param(
       embedded_test_server()->GetURL("origin.h.com", "/"), intermediate_url);
-  NavigateToURLAndWaitForRedirects(start_url, final_url);
+  NavigateToURLAndWaitForRedirects(start_url, intermediate_url);
 }
 
 // Test a long redirect chain that bounces through the original URL's domain,

components/debounce/browser/debounce_rule.cc

@@ -119,6 +119,14 @@ const std::string DebounceRule::GetETLDForDebounce(const std::string& host) {
                 EXCLUDE_PRIVATE_REGISTRIES);
 }
 
+// static
+bool DebounceRule::IsSameETLDForDebounce(const GURL& url1, const GURL& url2) {
+  return net::registry_controlled_domains::SameDomainOrHost(
+      url1, url2,
+      net::registry_controlled_domains::PrivateRegistryFilter::
+          EXCLUDE_PRIVATE_REGISTRIES);
+}
+
 // static
 base::expected<std::pair<std::vector<std::unique_ptr<DebounceRule>>,
                          base::flat_set<std::string>>,
@@ -308,7 +316,7 @@ bool DebounceRule::Apply(const GURL& original_url,
     return false;
 
   // Failsafe: never redirect to the same site.
-  if (url::IsSameOriginWith(original_url, new_url))
+  if (IsSameETLDForDebounce(original_url, new_url))
     return false;
 
   *final_url = new_url;

components/debounce/browser/debounce_rule.h

@@ -54,6 +54,7 @@ class DebounceRule {
                         std::string>
   ParseRules(const std::string& contents);
   static const std::string GetETLDForDebounce(const std::string& host);
+  static bool IsSameETLDForDebounce(const GURL& url1, const GURL& url2);
   static bool GetURLPatternSetFromValue(const base::Value* value,
                                         extensions::URLPatternSet* result);