OOPIF: Handle cross-site frames being blocked by X-Frame-Options or CSP.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index e33649f7e9db3c1e7fa85626e2a4bf8dc145298a..b09c451ffb96035529934ac3ebc5bf8d8046d317 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -550,6 +550,7 @@ bool RenderFrameHostImpl::OnMessageReceived(const IPC::Message &msg) {
                         OnDidChangeSandboxFlags)
     IPC_MESSAGE_HANDLER(FrameHostMsg_DidChangeFrameOwnerProperties,
                         OnDidChangeFrameOwnerProperties)
+    IPC_MESSAGE_HANDLER(FrameHostMsg_BlockedLoad, OnBlockedLoad)
     IPC_MESSAGE_HANDLER(FrameHostMsg_UpdateTitle, OnUpdateTitle)
     IPC_MESSAGE_HANDLER(FrameHostMsg_UpdateEncoding, OnUpdateEncoding)
     IPC_MESSAGE_HANDLER(FrameHostMsg_BeginNavigation,
@@ -1516,6 +1517,28 @@ void RenderFrameHostImpl::OnDidChangeFrameOwnerProperties(
   }
 }
 
+void RenderFrameHostImpl::OnBlockedLoad() {
+  // When a frame is blocked by X-Frame-Options or CSP frame-ancestors, the
+  // blocked frame needs to get a unique origin, which ensures that it
+  // appears as a normal cross-origin document, and is the desired behavior
+  // according to spec: https://www.w3.org/TR/CSP2/#directive-frame-ancestors
+  // This sets the unique origin on both the browser and renderer sides.  The
+  // IPC to renderer may be required when a cross-process subframe is blocked,
+  // since the blocking currently occurs in the pending RenderFrame, but the
+  // actual blocked frame will be left in the current RenderFrame in a
+  // different process.
+  //
+  // TODO(mkwst, alexmos): This will probably be called directly rather than
+  // from an renderer IPC once X-Frame-Options and CSP enforcement moves to the
+  // browser process (https://crbug.com/555418).
+  frame_tree_node_->SetCurrentOrigin(url::Origin());
+
+  if (this == frame_tree_node_->render_manager()->pending_frame_host()) {
+    RenderFrameHost* current_rfh = frame_tree_node_->current_frame_host();
+    current_rfh->Send(new FrameMsg_BlockedLoad(current_rfh->GetRoutingID()));
+  }
+}
+
 void RenderFrameHostImpl::OnUpdateTitle(
     const base::string16& title,
     blink::WebTextDirection title_direction) {
@@ -1557,11 +1580,22 @@ void RenderFrameHostImpl::OnDispatchLoad() {
   RenderFrameProxyHost* proxy =
       frame_tree_node()->render_manager()->GetProxyToParent();
   if (!proxy) {
+    // A valid special case where the proxy won't exist occurs when a frame
+    // gets blocked due to X-Frame-Options or CSP while it is still pending.
+    // (The proxy in the parent isn't created until commit.)  In that case, it
+    // is ok to ignore this load event dispatch, since it will be done as part
+    // of forwarding the blocked notification (see
+    // FrameMsg_CancelLoadAfterXFrameOptionsOrCSPDenied).
+    //
+    // TODO(mkwst, alexmos): This won't be necessary once X-Frame-Options and
+    // CSP enforcement moves to the browser process (https://crbug.com/555418).
+    if (this != frame_tree_node_->current_frame_host())
+      return;
+
     bad_message::ReceivedBadMessage(GetProcess(),
                                     bad_message::RFH_NO_PROXY_TO_PARENT);
     return;
   }
-
   proxy->Send(new FrameMsg_DispatchLoad(proxy->GetRoutingID()));
 }