Don't copy image buffer when calculating size.

src/image/SkImage_Gpu.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <cstddef>
 #include <cstring>
 #include <type_traits>
@@ skipping 468 matching lines @@
     int ctCount = 0;
     if (!isScaled && this->peekPixels(&pixmap)) {
         info = pixmap.info();
         pixelSize = SkAlign8(pixmap.getSafeSize());
         if (pixmap.ctable()) {
             ctCount = pixmap.ctable()->count();
             ctSize = SkAlign8(pixmap.ctable()->count() * 4);
         }
     } else {
         // Here we're just using presence of data to know whether there is a codec behind the image.
         // In the future we will access the cacherator and get the exact data that we want to (e.g.

[vmpstr, 2016/09/12 23:35:27]

nit: You should update the comment.

[cblume, 2016/09/13 00:02:26]

Done.

         // yuv planes) upload.
-        sk_sp<SkData> data(this->refEncoded());
+        SkImageCacherator* data(as_IB(this)->peekCacherator());

[vmpstr, 2016/09/12 23:35:27]

Can we just inline this in the if? I don't think we use data anywhere else.

[cblume, 2016/09/13 00:02:26]

Done. This actually makes it read much more easily to me as well:
if(!peekCache() && !peekPixels()) essentially.

         if (!data && !this->peekPixels(nullptr)) {
             return 0;
         }
         info = SkImageInfo::MakeN32(scaledSize.width(), scaledSize.height(), this->alphaType());
         pixelSize = SkAlign8(SkAutoPixmapStorage::AllocSize(info, nullptr));
         if (fillMode) {
             pixmap.alloc(info);
             if (isScaled) {
                 if (!this->scalePixels(pixmap, scaleFilterQuality,
                                        SkImage::kDisallow_CachingHint)) {
@@ skipping 207 matching lines @@
     }
     SkAutoTUnref<GrTexture> texture(GrUploadMipMapToTexture(ctx, info, texels, mipLevelCount));
     if (!texture) {
         return nullptr;
     }
     texture->texturePriv().setGammaTreatment(gammaTreatment);
     return sk_make_sp<SkImage_Gpu>(texture->width(), texture->height(), kNeedNewImageUniqueID,
                                    info.alphaType(), texture, sk_ref_sp(info.colorSpace()),
                                    budgeted);
 }