Add supportsInputMethod() interface for WebPlugin.

Source/core/plugins/PluginView.h

Index: Source/core/plugins/PluginView.h
diff --git a/Source/core/plugins/PluginView.h b/Source/core/plugins/PluginView.h
index 19d44534bbe76c573848fe91d8660b6c289a654f..fd40d40251e5ab2d95316b079a18c84680d5cf6e 100644
--- a/Source/core/plugins/PluginView.h
+++ b/Source/core/plugins/PluginView.h
@@ -49,6 +49,7 @@ public:
     virtual bool getFormValue(String&) { return false; }
     virtual bool wantsWheelEvents() { return false; }
     virtual bool supportsKeyboardFocus() const { return false; }
+    virtual bool supportsInputMethod() const { return false; }
     virtual bool canProcessDrag() const { return false; }
 
     virtual void didReceiveResponse(const ResourceResponse&) { }