Use FrameIsAd to decide whether to isolate a frame in TopDocumentIsolation mode.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 2a6c4cb5e480edfd3a234224490b7a75f09266c8..b3a32bfe8bca44e0cb7abe948fdbd53942e48463 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -19,6 +19,7 @@
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial_params.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
@@ -55,6 +56,7 @@
 #include "chrome/browser/nacl_host/nacl_browser_delegate_impl.h"
 #include "chrome/browser/net_benchmarking.h"
 #include "chrome/browser/notifications/platform_notification_service_impl.h"
+#include "chrome/browser/page_load_metrics/ads_detection.h"
 #include "chrome/browser/page_load_metrics/experiments/delay_navigation_throttle.h"
 #include "chrome/browser/page_load_metrics/metrics_navigation_throttle.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
@@ -1263,20 +1265,37 @@ void ChromeContentBrowserClient::OverrideNavigationParams(
 #endif
 }
 
-bool ChromeContentBrowserClient::
-    ShouldFrameShareParentSiteInstanceDespiteTopDocumentIsolation(
-        const GURL& url,
-        content::SiteInstance* parent_site_instance) {
-  if (IsNTPSiteInstance(parent_site_instance))
-    return true;
+bool ChromeContentBrowserClient::ShouldIsolateFrameForTopDocumentIsolation(
+    content::NavigationHandle* navigation_handle,
+    content::SiteInstance* main_frame_site_instance) {
+  if (IsNTPSiteInstance(main_frame_site_instance))
+    return false;
 
 #if BUILDFLAG(ENABLE_EXTENSIONS)
-  return ChromeContentBrowserClientExtensionsPart::
-      ShouldFrameShareParentSiteInstanceDespiteTopDocumentIsolation(
-          url, parent_site_instance);
-#else
-  return false;
+  if (ChromeContentBrowserClientExtensionsPart::
+          IsMainFrameSiteInstanceExcludedFromTopDocumentIsolation(
+              main_frame_site_instance)) {
+    return false;
+  }
 #endif
+
+  features::TopDocumentIsolationMode tdiMode =
+      static_cast<features::TopDocumentIsolationMode>(
+          base::GetFieldTrialParamByFeatureAsInt(
+              ::features::kTopDocumentIsolation,
+              ::features::kTopDocumentIsolationModeParam,
+              static_cast<int>(
+                  features::TopDocumentIsolationMode::Unspecified)));
+  switch (tdiMode) {
+    case features::TopDocumentIsolationMode::Unspecified:
+    case features::TopDocumentIsolationMode::Ads:
+      return page_load_metrics::GetDetectedAdTypes(navigation_handle).any();
+
+    case features::TopDocumentIsolationMode::CrossSite:
+      return true;
+  }
+  NOTREACHED();
+  return false;
 }
 
 bool ChromeContentBrowserClient::IsSuitableHost(