Bug 1242794 - make SkGrPixelRef::deepCopy preserve alpha type. r=jmuizelaar

--HG--
extra : rebase_source : 5406d41a892877f3cbcf4bb6386b46d16ef3eca1

gfx/skia/skia/src/gpu/SkGrPixelRef.cpp

@@ -51,7 +51,8 @@ bool SkROLockPixelsPixelRef::onLockPixelsAreWritable() const {
 ///////////////////////////////////////////////////////////////////////////////
 
 static SkGrPixelRef* copy_to_new_texture_pixelref(GrTexture* texture, SkColorType dstCT,
-                                                  SkColorProfileType dstPT, const SkIRect* subset) {
+                                                  SkAlphaType dstAT, SkColorProfileType dstPT,
+                                                  const SkIRect* subset) {
     if (nullptr == texture || kUnknown_SkColorType == dstCT) {
         return nullptr;
     }
@@ -75,7 +76,7 @@ static SkGrPixelRef* copy_to_new_texture_pixelref(GrTexture* texture, SkColorTyp
         srcRect = *subset;
     }
     desc.fFlags = kRenderTarget_GrSurfaceFlag;
-    desc.fConfig = SkImageInfo2GrPixelConfig(dstCT, kPremul_SkAlphaType, dstPT);
+    desc.fConfig = SkImageInfo2GrPixelConfig(dstCT, dstAT, dstPT);
 
     GrTexture* dst = context->textureProvider()->createTexture(desc, false, nullptr, 0);
     if (nullptr == dst) {
@@ -88,8 +89,7 @@ static SkGrPixelRef* copy_to_new_texture_pixelref(GrTexture* texture, SkColorTyp
     context->copySurface(dst->asRenderTarget(), texture, srcRect, SkIPoint::Make(0,0),
                          GrContext::kFlushWrites_PixelOp);
 
-    SkImageInfo info = SkImageInfo::Make(desc.fWidth, desc.fHeight, dstCT, kPremul_SkAlphaType,
-                                         dstPT);
+    SkImageInfo info = SkImageInfo::Make(desc.fWidth, desc.fHeight, dstCT, dstAT, dstPT);
     SkGrPixelRef* pixelRef = new SkGrPixelRef(info, dst);
     SkSafeUnref(dst);
     return pixelRef;
@@ -142,7 +142,8 @@ SkPixelRef* SkGrPixelRef::deepCopy(SkColorType dstCT, SkColorProfileType dstPT,
     // a GrTexture owned elsewhere (e.g., SkGpuDevice), and cannot live
     // independently of that texture.  Texture-backed pixel refs, on the other
     // hand, own their GrTextures, and are thus self-contained.
-    return copy_to_new_texture_pixelref(fSurface->asTexture(), dstCT, dstPT, subset);
+    return copy_to_new_texture_pixelref(fSurface->asTexture(), dstCT, this->info().alphaType(),
+                                        dstPT, subset);
 }
 
 static bool tryAllocBitmapPixels(SkBitmap* bitmap) {