Adding MimeHandlerView.

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index ada672f46ecc109e9fa3f853426a8420e8d0f26a..82484f65c5db83dc21c8283bd462a40e2c35c9a4 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -89,10 +89,13 @@ class CONTENT_EXPORT ContentRendererClient {
   // Allows the embedder to override creating a plugin. If it returns true, then
   // |plugin| will contain the created plugin, although it could be NULL. If it
   // returns false, the content layer will create the plugin.
+  // |instance_id| will be filled in if we need to create a MimeHandlerView
+  // plugin.
   virtual bool OverrideCreatePlugin(
       RenderFrame* render_frame,
       blink::WebLocalFrame* frame,
       const blink::WebPluginParams& params,
+      int* instance_id,
       blink::WebPlugin** plugin);
 
   // Creates a replacement plug-in that is shown when the plug-in at |file_path|