Blink: Replace all "plug-in" with "plugin".

Source/core/layout/LayoutPart.cpp

Index: Source/core/layout/LayoutPart.cpp
diff --git a/Source/core/layout/LayoutPart.cpp b/Source/core/layout/LayoutPart.cpp
index 08b444d5826e051641205e7a51c6c5f5d6b80649..42e384983949c1dd6b220cc9b89fa76b5030da28 100644
--- a/Source/core/layout/LayoutPart.cpp
+++ b/Source/core/layout/LayoutPart.cpp
@@ -220,7 +220,7 @@ void LayoutPart::paintContents(const PaintInfo& paintInfo, const LayoutPoint& pa
 CursorDirective LayoutPart::getCursor(const LayoutPoint& point, Cursor& cursor) const
 {
     if (widget() && widget()->isPluginView()) {
-        // A plug-in is responsible for setting the cursor when the pointer is over it.
+        // A plugin is responsible for setting the cursor when the pointer is over it.
         return DoNotSetCursor;
     }
     return LayoutReplaced::getCursor(point, cursor);