Replicate sandbox flags for OOPIF (Blink part 2)

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index d93f1b81c51cecd8a2f4031ea20e3b04611e3fad..8a962b1d6e641eb7f07ab34ba898f9b1c45a093b 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -1377,9 +1377,11 @@ void FrameLoader::dispatchDidClearWindowObjectInMainWorld()
 SandboxFlags FrameLoader::effectiveSandboxFlags() const
 {
     SandboxFlags flags = m_forcedSandboxFlags;
-    // FIXME: We need a way to propagate sandbox flags to out-of-process frames.
     if (FrameOwner* frameOwner = m_frame->owner())
         flags |= frameOwner->sandboxFlags();
+    // Frames need to inherit the sandbox flags of their parent frame.
+    if (Frame* parentFrame = m_frame->tree().parent())
+        flags |= parentFrame->securityContext()->sandboxFlags();

[Nate Chapin, 2015/01/22 19:00:28]

This is ok, but I can't help but feel that we should only need to do one of
these to get all the required flags.

[dcheng, 2015/01/22 19:05:53]

I guess the counter-argument is it's nice to have one place do all the
calculations for this.

     return flags;
 }