Add infrastructure to instantiate a helper plugin.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 3449f3e569f3d305794f969353f32413c74d7a0b..78a0ae81dba7837dc029d024efa727794f659c20 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -23,6 +23,7 @@
 #include "ipc/ipc_sync_message.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCursorInfo.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebHelperPlugin.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPagePopup.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPopupMenu.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPopupMenuInfo.h"
@@ -150,6 +151,8 @@ WebWidget* RenderWidget::CreateWebWidget(RenderWidget* render_widget) {
       return WebPopupMenu::create(render_widget);
     case WebKit::WebPopupTypePage:
       return WebPagePopup::create(render_widget);
+    case WebKit::WebPopupTypeHelperPlugin:

[jamesr, 2012/06/22 18:46:42]

how is this case different from a full-page plugin? why does it need a separate
popup_type_ ?

[ddorwin, 2012/06/22 19:39:19]

This is an off-screen page that instantiates a specified plugin. The intent is
that Chrome can instantiate this plugin to provide capabilities (transparent to
the web application). Thus, the term "helper plugin". Thus, it's not a full-page
plugin or a traditional pop-up.

On 2012/06/22 18:46:42, jamesr wrote:
The plugin is not visible or part of the page. It is a separate widget.
The implementation requires a separate WebWidget class (WebHelperPlugin).
WebWidgets can currently only be created by Chrome in this function using the
popup_type_ enum. As mentioned in http://webk.it/87399#c6, it might make senee
to refactor this code since popup_type_ is only used in this initialization
function.

+      return WebKit::WebHelperPlugin::create(render_widget);
     default:
       NOTREACHED();
   }