change setAlphaType to not modify the pixelref's genID

src/core/SkPixelRef.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkPixelRef.h"
 #include "SkFlattenableBuffers.h"
 #include "SkThread.h"
@@ skipping 236 matching lines @@
     // We don't invalidate ourselves if we think another SkPixelRef is sharing our genID.
     if (fUniqueGenerationID) {
         for (int i = 0; i < fGenIDChangeListeners.count(); i++) {
             fGenIDChangeListeners[i]->onChange();
         }
     }
     // Listeners get at most one shot, so whether these triggered or not, blow them away.
     fGenIDChangeListeners.deleteAll();
 }
 
-void SkPixelRef::notifyPixelsChanged(SkAlphaType at) {
+void SkPixelRef::notifyPixelsChanged() {
 #ifdef SK_DEBUG
     if (fIsImmutable) {
         SkDebugf("========== notifyPixelsChanged called on immutable pixelref");
     }
 #endif
-    *const_cast<SkAlphaType*>(&fInfo.fAlphaType) = at;
     this->callGenIDChangeListeners();
     this->needsNewGenID();
 }
 
+void SkPixelRef::changeAlphaType(SkAlphaType at) {
+    *const_cast<SkAlphaType*>(&fInfo.fAlphaType) = at;
+}
+
 void SkPixelRef::setImmutable() {
     fIsImmutable = true;
 }
 
 bool SkPixelRef::readPixels(SkBitmap* dst, const SkIRect* subset) {
     return this->onReadPixels(dst, subset);
 }
 
 bool SkPixelRef::onReadPixels(SkBitmap* dst, const SkIRect* subset) {
     return false;
@@ skipping 34 matching lines @@
 
 #ifdef SK_BUILD_FOR_ANDROID
 void SkPixelRef::globalRef(void* data) {
     this->ref();
 }
 
 void SkPixelRef::globalUnref() {
     this->unref();
 }
 #endif