Turn on AreCrossProcessFramesPossible by default.

content/common/site_isolation_policy.cc

Index: content/common/site_isolation_policy.cc
diff --git a/content/common/site_isolation_policy.cc b/content/common/site_isolation_policy.cc
index 5a4748787a08c4425f238f60d182f541f32a0517..a1607c84caf590d76586f467d1c0f2ff9867fb3a 100644
--- a/content/common/site_isolation_policy.cc
+++ b/content/common/site_isolation_policy.cc
@@ -5,21 +5,13 @@
 #include "content/common/site_isolation_policy.h"
 
 #include "base/command_line.h"
-#include "base/feature_list.h"
-#include "base/lazy_instance.h"
-#include "content/public/common/browser_side_navigation_policy.h"
-#include "content/public/common/content_client.h"
-#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 
 namespace content {
 
 // static
 bool SiteIsolationPolicy::AreCrossProcessFramesPossible() {
-  return UseDedicatedProcessesForAllSites() ||
-         IsTopDocumentIsolationEnabled() ||
-         GetContentClient()->IsSupplementarySiteIsolationModeEnabled() ||
-         base::FeatureList::IsEnabled(::features::kGuestViewCrossProcessFrames);
+  return true;
 }
 
 // static