Alter SkXfermode's asFragmentProcessor & asXPFactory contracts

src/utils/debugger/SkOverdrawMode.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorPriv.h"
 #include "SkOverdrawMode.h"
 #include "SkString.h"
@@ skipping 273 matching lines @@
             nextIdx = 11 - (SkColorGetG(dst)+22)/45;
         }
         SkASSERT(nextIdx < (int)SK_ARRAY_COUNT(gTable));
 
         return gTable[nextIdx];
     }
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkOverdrawXfermode)
 
 #if SK_SUPPORT_GPU
-    bool asFragmentProcessor(const GrFragmentProcessor** output,
-                             const GrFragmentProcessor* dst) const override {
-        if (output) {
-            *output = GrOverdrawFP::Create(dst);
-        }
-        return true;
+    const GrFragmentProcessor* asFragmentProcessor(const GrFragmentProcessor* dst) const override {
+        return GrOverdrawFP::Create(dst);
     }
 
-    bool asXPFactory(GrXPFactory** xpf) const override {
-        if (xpf) {
-            *xpf = GrOverdrawXPFactory::Create();
-        }
-        return true;
+    GrXPFactory* asXPFactory() const override {
+        return GrOverdrawXPFactory::Create();
     }
 #endif
 
 #ifndef SK_IGNORE_TO_STRING
     void toString(SkString* str) const override { str->set("SkOverdrawXfermode"); }
 #endif
 
 private:
     friend class SkOverdrawMode;
 
     void flatten(SkWriteBuffer& buffer) const override { }
 
     typedef SkXfermode INHERITED;
 };
 
 SkFlattenable* SkOverdrawXfermode::CreateProc(SkReadBuffer& buffer) {
     return Create();
 }
 
 SkXfermode* SkOverdrawMode::Create() { return new SkOverdrawXfermode; }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkOverdrawMode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkOverdrawXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END