Remove isOpaque from SkSpecialImage, just use alpha type

src/core/SkSpecialImage.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 "SkSpecialImage.h"
 #include "SkBitmap.h"
 #include "SkImage.h"
@@ skipping 87 matching lines @@
     }
 
     sk_sp<GrTexture> resultTex(GrRefCachedBitmapTexture(context,
                                                         bmp,
                                                         GrTextureParams::ClampNoFilter(),
                                                         SkSourceGammaTreatment::kRespect));
     if (!resultTex) {
         return nullptr;
     }
 
-    SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
-
     return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(resultTex->width(), resultTex->height()),
                                        this->uniqueID(),
                                        resultTex, sk_ref_sp(this->getColorSpace()), &this->props(),
-                                       at);
+                                       this->alphaType());
 #else
     return nullptr;
 #endif
 }
 
 void SkSpecialImage::draw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint) const {
     return as_SIB(this)->onDraw(canvas, x, y, paint);
 }
 
 bool SkSpecialImage::getROPixels(SkBitmap* bm) const {
@@ skipping 89 matching lines @@
     {
         SkASSERT(bm.pixelRef());
 
         // We have to lock now, while bm is still in scope, since it may have come from our
         // cache, which means we need to keep it locked until we (the special) are done, since
         // we cannot re-generate the cache entry (if bm came from a generator).
         fBitmap.lockPixels();
         SkASSERT(fBitmap.getPixels());
     }
 
-    bool isOpaque() const override { return fBitmap.isOpaque(); }
+    SkAlphaType alphaType() const override { return fBitmap.alphaType(); }
 
     size_t getSize() const override { return fBitmap.getSize(); }
 
     void onDraw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint) const override {
         SkRect dst = SkRect::MakeXYWH(x, y,
                                       this->subset().width(), this->subset().height());
 
         canvas->drawBitmapRect(fBitmap, this->subset(),
                                dst, paint, SkCanvas::kStrict_SrcRectConstraint);
     }
@@ skipping 93 matching lines @@
         , fColorSpace(std::move(colorSpace))
         , fAddedRasterVersionToCache(false) {
     }
 
     ~SkSpecialImage_Gpu() override {
         if (fAddedRasterVersionToCache.load()) {
             SkNotifyBitmapGenIDIsStale(this->uniqueID());
         }
     }
 
-    bool isOpaque() const override {
-        return GrPixelConfigIsOpaque(fTexture->config()) || fAlphaType == kOpaque_SkAlphaType;
-    }
+    SkAlphaType alphaType() const override { return fAlphaType; }
 
     size_t getSize() const override { return fTexture->gpuMemorySize(); }
 
     void onDraw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint) const override {
         SkRect dst = SkRect::MakeXYWH(x, y,
                                       this->subset().width(), this->subset().height());
 
         auto img = sk_sp<SkImage>(new SkImage_Gpu(fTexture->width(), fTexture->height(),
                                                   this->uniqueID(), fAlphaType, fTexture.get(),
                                                   fColorSpace, SkBudgeted::kNo));
 
         canvas->drawImageRect(img, this->subset(),
                                dst, paint, SkCanvas::kStrict_SrcRectConstraint);
     }
 
     GrTexture* onPeekTexture() const override { return fTexture.get(); }
 
     sk_sp<GrTexture> onAsTextureRef(GrContext*) const override { return fTexture; }
 
     bool onGetROPixels(SkBitmap* dst) const override {
         if (SkBitmapCache::Find(this->uniqueID(), dst)) {
             SkASSERT(dst->getGenerationID() == this->uniqueID());
             SkASSERT(dst->isImmutable());
             SkASSERT(dst->getPixels());
             return true;
         }
 
         SkImageInfo info = SkImageInfo::MakeN32(this->width(), this->height(),
-                                                this->isOpaque() ? kOpaque_SkAlphaType
-                                                                 : kPremul_SkAlphaType,
-                                                fColorSpace);
+                                                this->alphaType(), fColorSpace);
 
         if (!dst->tryAllocPixels(info)) {
             return false;
         }
 
         if (!fTexture->readPixels(0, 0, dst->width(), dst->height(), kSkia8888_GrPixelConfig,
                                   dst->getPixels(), dst->rowBytes())) {
             return false;
         }
 
@@ skipping 71 matching lines @@
                                                   sk_sp<GrTexture> tex,
                                                   sk_sp<SkColorSpace> colorSpace,
                                                   const SkSurfaceProps* props,
                                                   SkAlphaType at) {
     SkASSERT(rect_fits(subset, tex->width(), tex->height()));
     return sk_make_sp<SkSpecialImage_Gpu>(subset, uniqueID, std::move(tex), at,
                                           std::move(colorSpace), props);
 }
 
 #endif