Harden the machinery around updateWidgetPositions()

Source/core/rendering/RenderWidget.cpp

Index: Source/core/rendering/RenderWidget.cpp
diff --git a/Source/core/rendering/RenderWidget.cpp b/Source/core/rendering/RenderWidget.cpp
index f74f21c7c9c4f20af7efc36fb23074ac70cdf0b5..ca9fa8433a68586894238a62c691b8818fdc8883 100644
--- a/Source/core/rendering/RenderWidget.cpp
+++ b/Source/core/rendering/RenderWidget.cpp
@@ -32,7 +32,6 @@
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
-#include "platform/graphics/GraphicsContext.h"
 #include "wtf/HashMap.h"
 
 namespace WebCore {
@@ -88,19 +87,18 @@ static void moveWidgetToParentSoon(Widget* child, FrameView* parent)
 RenderWidget::RenderWidget(Element* element)
     : RenderReplaced(element)
     , m_widget(0)
-    , m_frameView(element->document().view())
     // Reference counting is used to prevent the widget from being
     // destroyed while inside the Widget code, which might not be
     // able to handle that.
     , m_refCount(1)
 {
-    view()->addWidget(this);
+    ASSERT(element);
+    frameView()->addWidget(this);
 }
 
 void RenderWidget::willBeDestroyed()
 {
-    if (RenderView* v = view())
-        v->removeWidget(this);
+    frameView()->removeWidget(this);
 
     if (AXObjectCache* cache = document().existingAXObjectCache()) {
         cache->childrenChanged(this->parent());
@@ -199,7 +197,7 @@ void RenderWidget::setWidget(PassRefPtr<Widget> widget)
                 repaint();
             }
         }
-        moveWidgetToParentSoon(m_widget.get(), m_frameView);
+        moveWidgetToParentSoon(m_widget.get(), frameView());
     }
 
     if (AXObjectCache* cache = document().existingAXObjectCache())
@@ -278,7 +276,7 @@ void RenderWidget::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
     if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && hasOutline())
         paintOutline(paintInfo, LayoutRect(adjustedPaintOffset, size()));
 
-    if (!m_frameView || paintInfo.phase != PaintPhaseForeground)
+    if (paintInfo.phase != PaintPhaseForeground)
         return;
 
     if (style()->hasBorderRadius()) {