Introduce support for origins that require process isolation.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 74b3229efd65f3d067a917ea2a2c17b7bcdfd5a8..f7b8fc8763f3e6801a853b1124f29fe246cce2c4 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -53,6 +53,7 @@
 #include "components/tracing/common/tracing_switches.h"
 #include "components/viz/display_compositor/host_shared_bitmap_manager.h"
 #include "content/browser/browser_thread_impl.h"
+#include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/dom_storage/dom_storage_area.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/download/save_file_manager.h"
@@ -798,6 +799,13 @@ void BrowserMainLoop::PostMainMessageLoopStart() {
     LevelDBWrapperImpl::EnableAggressiveCommitDelay();
   }
 
+  if (parsed_command_line_.HasSwitch(switches::kIsolateOrigins)) {
+    ChildProcessSecurityPolicyImpl* policy =
+        ChildProcessSecurityPolicyImpl::GetInstance();
+    policy->AddIsolatedOriginsFromCommandLine(
+        parsed_command_line_.GetSwitchValueASCII(switches::kIsolateOrigins));
+  }
+
   // Enable memory-infra dump providers.
   InitSkiaEventTracer();
   tracing::ProcessMetricsMemoryDumpProvider::RegisterForProcess(