use onPeekBitmap instead of asLegacyBitmap

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 c795d54fcbb0aaf68bbd63c7e034cfda8e0f7af4..44bb71c0889ab311977e4929271b8e6506e94c29 100644
--- a/src/image/SkImage_Gpu.cpp
+++ b/src/image/SkImage_Gpu.cpp
@@ -315,12 +315,12 @@ sk_sp<SkImage> SkImage::makeTextureImage(GrContext *context) const {
         GrImageTextureMaker maker(context, cacher, this, kDisallow_CachingHint);
         return create_image_from_maker(&maker, at, this->uniqueID());
     }
-    SkBitmap bmp;
-    if (!this->asLegacyBitmap(&bmp, kRO_LegacyBitmapMode)) {
-        return nullptr;
+

[robertphillips, 2016/08/08 14:32:29]

How do we know we're not in the SkImage_Generator case?

[reed1, 2016/08/08 15:19:30]

Generator's have a cacherator (by definition), so they will be caught on line
314.

That said, I'll double check that we have a unittest for this API that covers
all of the image backing types [ texture, generator, raster ]

+    if (const SkBitmap* bmp = as_IB(this)->onPeekBitmap()) {
+        GrBitmapTextureMaker maker(context, *bmp);
+        return create_image_from_maker(&maker, at, this->uniqueID());
     }
-    GrBitmapTextureMaker maker(context, bmp);
-    return create_image_from_maker(&maker, at, this->uniqueID());
+    return nullptr;
 }
 
 sk_sp<SkImage> SkImage::makeNonTextureImage() const {