Remove command line/field trial support and configs for Isolate Extensions.

chrome/common/extensions/extension_process_policy.cc

Index: chrome/common/extensions/extension_process_policy.cc
diff --git a/chrome/common/extensions/extension_process_policy.cc b/chrome/common/extensions/extension_process_policy.cc
index 5b2c81402c7599413d1ee5b160610353e168ada2..2b7041b905e68a45b61c0f4677eac823d67ce2b4 100644
--- a/chrome/common/extensions/extension_process_policy.cc
+++ b/chrome/common/extensions/extension_process_policy.cc
@@ -4,11 +4,8 @@
 
 #include "chrome/common/extensions/extension_process_policy.h"
 
-#include "base/command_line.h"
-#include "base/metrics/field_trial.h"
 #include "base/strings/string_util.h"
 #include "chrome/common/extensions/extension_constants.h"
-#include "content/public/common/content_switches.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_set.h"
@@ -68,19 +65,4 @@ bool CrossesExtensionProcessBoundary(
   return old_url_extension != new_url_extension;
 }
 
-bool IsIsolateExtensionsEnabled() {
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kIsolateExtensions) ||
-      base::CommandLine::ForCurrentProcess()->HasSwitch(
-          ::switches::kSitePerProcess)) {
-    return true;
-  }
-
-  const std::string group_name =
-      base::FieldTrialList::FindFullName("SiteIsolationExtensions");
-  // Use StartsWith() for more flexibility (e.g. multiple Enabled groups).
-  return !base::StartsWith(group_name, "Control",
-                           base::CompareCase::INSENSITIVE_ASCII);
-}
-
 }  // namespace extensions