change more effects to only expose factories

include/effects/SkModeColorFilter.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkModeColorFilter_DEFINED
 #define SkModeColorFilter_DEFINED
 
 #include "SkColorFilter.h"
 #include "SkColorPriv.h"
 #include "SkString.h"
 #include "SkXfermode.h"
 
 class SkModeColorFilter : public SkColorFilter {
 public:
-    SkModeColorFilter(SkColor color, SkXfermode::Mode mode) {
-        fColor = color;
-        fMode = mode;
-        this->updateCache();
-    };
+    static SkColorFilter* Create(SkColor color, SkXfermode::Mode mode) {
+        return new SkModeColorFilter(color, mode);
+    }
 
     SkColor getColor() const { return fColor; }
     SkXfermode::Mode getMode() const { return fMode; }
     SkPMColor getPMColor() const { return fPMColor; }
 
     bool asColorMode(SkColor*, SkXfermode::Mode*) const override;
     uint32_t getFlags() const override;
     void filterSpan(const SkPMColor shader[], int count, SkPMColor result[]) const override;
 
 #ifndef SK_IGNORE_TO_STRING
     void toString(SkString* str) const override {
         str->append("SkModeColorFilter: color: 0x");
         str->appendHex(fColor);
         str->append(" mode: ");
         str->append(SkXfermode::ModeName(fMode));
     }
 #endif
 
 #if SK_SUPPORT_GPU
     const GrFragmentProcessor* asFragmentProcessor(GrContext*) const override;
 #endif
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkModeColorFilter)
 
 protected:
+    SkModeColorFilter(SkColor color, SkXfermode::Mode mode) {
+        fColor = color;
+        fMode = mode;
+        this->updateCache();
+    };
+
     void flatten(SkWriteBuffer&) const override;
 
 private:
     SkColor             fColor;
     SkXfermode::Mode    fMode;
     // cache
     SkPMColor           fPMColor;
     SkXfermodeProc      fProc;
 
     void updateCache();
 
     typedef SkColorFilter INHERITED;
 };
 
 #endif