Remove unused field m_outsets

Review URL: https://codereview.chromium.org/462403002

git-svn-id: svn://svn.chromium.org/blink/trunk@180183 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/rendering/FilterEffectRenderer.h

@@ -114,8 +114,6 @@ private:
     RefPtr<SourceGraphic> m_sourceGraphic;
     RefPtr<FilterEffect> m_lastEffect;
 
-    IntRectExtent m_outsets;
-
     bool m_graphicsBufferAttached;
     bool m_hasFilterThatMovesPixels;
 };