Prepare to replicate sandbox flags for OOPIF

Source/core/dom/SecurityContext.cpp

Index: Source/core/dom/SecurityContext.cpp
diff --git a/Source/core/dom/SecurityContext.cpp b/Source/core/dom/SecurityContext.cpp
index 68a4d5992527ea9812bbc2e0afda2baa78fd1a44..2b7d6266e1221f4fe7a01f85240e6dc876b4ac14 100644
--- a/Source/core/dom/SecurityContext.cpp
+++ b/Source/core/dom/SecurityContext.cpp
@@ -34,6 +34,7 @@ namespace blink {
 
 SecurityContext::SecurityContext()
     : m_haveInitializedSecurityOrigin(false)
+    , m_sandboxFlags(SandboxNone)
 {
 }
 
@@ -64,4 +65,15 @@ bool SecurityContext::isSecureTransitionTo(const KURL& url) const
     return securityOrigin()->canAccess(other.get());
 }
 
+void SecurityContext::enforceSandboxFlags(SandboxFlags mask)
+{
+    m_sandboxFlags |= mask;
+
+    // The SandboxOrigin is stored redundantly in the security origin.
+    if (isSandboxed(SandboxOrigin) && securityOrigin() && !securityOrigin()->isUnique()) {
+        setSecurityOrigin(SecurityOrigin::createUnique());
+        didUpdateSecurityOrigin();
+    }
+}
+
 }