Move plugins to be stored in HTMLPlugInElement.

third_party/WebKit/Source/core/layout/LayoutPart.h

Index: third_party/WebKit/Source/core/layout/LayoutPart.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutPart.h b/third_party/WebKit/Source/core/layout/LayoutPart.h
index 9a48047a851ef5106d944bbd28ebec283a809463..244cdc7dbe4ccbc4e039502947158bc3d244831e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutPart.h
+++ b/third_party/WebKit/Source/core/layout/LayoutPart.h
@@ -25,6 +25,7 @@
 
 #include "core/CoreExport.h"
 #include "core/layout/LayoutReplaced.h"
+#include "core/plugins/PluginView.h"
 #include "platform/FrameViewBase.h"
 
 namespace blink {
@@ -49,6 +50,7 @@ class CORE_EXPORT LayoutPart : public LayoutReplaced {
   void deref();
 
   FrameViewBase* frameViewBase() const;
+  PluginView* plugin() const;
 
   LayoutRect replacedContentRect() const final;