Revert of change all factories to return their base-class

include/effects/SkColorMatrixFilter.h

 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkColorMatrixFilter_DEFINED
 #define SkColorMatrixFilter_DEFINED
 
 #include "SkColorFilter.h"
 #include "SkColorMatrix.h"
 
 class SK_API SkColorMatrixFilter : public SkColorFilter {
 public:
-    static SkColorFilter* Create(const SkColorMatrix& cm) {
+    static SkColorMatrixFilter* Create(const SkColorMatrix& cm) {
         return new SkColorMatrixFilter(cm);
     }
-    static SkColorFilter* Create(const SkScalar array[20]) {
+    static SkColorMatrixFilter* Create(const SkScalar array[20]) {
         return new SkColorMatrixFilter(array);
     }
 
     void filterSpan(const SkPMColor src[], int count, SkPMColor[]) const override;
     uint32_t getFlags() const override;
     bool asColorMatrix(SkScalar matrix[20]) const override;
     SkColorFilter* newComposed(const SkColorFilter*) const override;
 
 #if SK_SUPPORT_GPU
     const GrFragmentProcessor* asFragmentProcessor(GrContext*) const override;
@@ skipping 23 matching lines @@
     Proc        fProc;
     State       fState;
     uint32_t    fFlags;
 
     void initState(const SkScalar array[20]);
 
     typedef SkColorFilter INHERITED;
 };
 
 #endif