Bug 1394005 Fix overloaded-virtual warnings in FilterNodeD2D1 r=froydnj

This warning is telling us that we have declared a function in a derived class
with the same name as a virtual function in a base class. The base class functions
can never be called.

In FilterNodeD2D1 we intend to do this (the base class methods are all MOZ_CRASH).
We silence the warning by importing those functions as private so they cannot be
called.

MozReview-Commit-ID: 6ENLKFMMBRy

--HG--
extra : rebase_source : 4230c85f4dca942fad6da347cef341aed5535734

gfx/2d/FilterNodeD2D1.h

@@ -69,6 +69,10 @@ protected:
   std::vector<RefPtr<FilterNodeD2D1>> mInputFilters;
   std::vector<RefPtr<SourceSurface>> mInputSurfaces;
   FilterType mType;
+
+private:
+  using FilterNode::SetAttribute;
+  using FilterNode::SetInput;
 };
 
 class FilterNodeConvolveD2D1 : public FilterNodeD2D1
@@ -87,6 +91,9 @@ public:
   virtual ID2D1Effect* InputEffect() override;
 
 private:
+  using FilterNode::SetAttribute;
+  using FilterNode::SetInput;
+
   void UpdateChain();
   void UpdateOffset();
   void UpdateSourceRect();