Add PostMessage support for MimeHandlerView

content/public/renderer/browser_plugin_delegate.h

Index: content/public/renderer/browser_plugin_delegate.h
diff --git a/content/public/renderer/browser_plugin_delegate.h b/content/public/renderer/browser_plugin_delegate.h
index 282adda24a47510931e68fde57ac1244955039b5..dac56de15dd95615551507abecd40ff4a6ae3248 100644
--- a/content/public/renderer/browser_plugin_delegate.h
+++ b/content/public/renderer/browser_plugin_delegate.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "content/common/content_export.h"
+#include "v8/include/v8.h"
 
 namespace content {
 
@@ -33,6 +34,9 @@ class CONTENT_EXPORT BrowserPluginDelegate {
   // Sets the instance ID that idenfies the plugin within current render
   // process.
   virtual void SetElementInstanceID(int element_instance_id) {}
+
+  // Return a scriptable object for the plugin.
+  virtual v8::Local<v8::Object> v8ScriptableObject(v8::Isolate*);
 };
 
 }  // namespace content