Don't copy image buffer when calculating size.

src/image/SkImage_Gpu.cpp

Index: src/image/SkImage_Gpu.cpp
diff --git a/src/image/SkImage_Gpu.cpp b/src/image/SkImage_Gpu.cpp
index c9315bb14de24ad4f30186590b40d8b21743eb4a..e2c5c36c1378a908f00c2c8a6e6989d3f3905847 100644
--- a/src/image/SkImage_Gpu.cpp
+++ b/src/image/SkImage_Gpu.cpp
@@ -485,11 +485,7 @@ size_t SkImage::getDeferredTextureImageData(const GrContextThreadSafeProxy& prox
             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.
-        // yuv planes) upload.
-        sk_sp<SkData> data(this->refEncoded());
-        if (!data && !this->peekPixels(nullptr)) {
+        if (!as_IB(this)->canGenerateTexture(proxy)) {

[reed1, 2016/10/24 13:42:00]

Is the predicate reversed here? If the image *can* generate a texture, than we
should just return (nothing CPU expensive to cache). If it cannot, then we
should proceed with extracting its pixels...

[cblume, 2016/10/25 02:51:01]

Done.

             return 0;
         }
         info = as_IB(this)->onImageInfo().makeWH(scaledSize.width(), scaledSize.height());