Merge RenderWidget into single subclass, RenderPart

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index 9eceb89f61840f4e1ec6bb68c26c01f8385a43f3..ef815b0c6eaa9b876b9beff26b045dd228144bd7 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -403,7 +403,6 @@ public:
     virtual bool isTextControl() const { return false; }
     virtual bool isTextField() const { return false; }
     virtual bool isVideo() const { return false; }
-    virtual bool isWidget() const { return false; }
 
     bool isDocumentElement() const { return document().documentElement() == m_node; }
     // isBody is called from RenderBox::styleWillChange and is thus quite hot.
@@ -634,7 +633,7 @@ public:
         return isPseudoElement() ? 0 : node();
     }
 
-    // FIXME: Why does RenderWidget need this?
+    // FIXME: Why does RenderPart need this?

[dsinclair, 2014/10/10 19:50:39]

Sorry, I meant, can you stick the crbug on to the end of the FIXME. Makes it
easy in the future if you're looking at the bug to find the places in the code
by grepping for the id.

[Zeeshan Qureshi, 2014/10/10 20:24:23]

Done.

     void clearNode() { m_node = nullptr; }
 
     // Returns the styled node that caused the generation of this renderer.