Add a second line of defense for receiving a bad message in the renderer.

content/renderer/render_view.cc

Index: content/renderer/render_view.cc
diff --git a/content/renderer/render_view.cc b/content/renderer/render_view.cc
index 91d9c2d1b830ccf86ef71d2eb6598593e6043699..53932d2766389321622a49bd5b1c9ce0d18c3ea6 100644
--- a/content/renderer/render_view.cc
+++ b/content/renderer/render_view.cc
@@ -581,7 +581,8 @@ bool RenderView::OnMessageReceived(const IPC::Message& message) {
       return true;
 
   bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(RenderView, message)
+  bool msg_is_ok = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(RenderView, message, msg_is_ok)
     IPC_MESSAGE_HANDLER(ViewMsg_Navigate, OnNavigate)
     IPC_MESSAGE_HANDLER(ViewMsg_Stop, OnStop)
     IPC_MESSAGE_HANDLER(ViewMsg_ReloadFrame, OnReloadFrame)
@@ -688,6 +689,13 @@ bool RenderView::OnMessageReceived(const IPC::Message& message) {
     // Have the super handle all other messages.
     IPC_MESSAGE_UNHANDLED(handled = RenderWidget::OnMessageReceived(message))
   IPC_END_MESSAGE_MAP()
+
+  if (!msg_is_ok) {
+    // The message had a handler, but its deserialization failed.
+    // Kill the renderer to avoid potential spoofing attacks.
+    CHECK(false) << "Unable to deserialize message in RenderView.";
+  }
+
   return handled;
 }