Stop wrapping images backed by generators as bitmaps in SkGpuDevice (except when tiling)

src/image/SkImage_Base.h

Index: src/image/SkImage_Base.h
diff --git a/src/image/SkImage_Base.h b/src/image/SkImage_Base.h
index 5cb6a48132c997746623c58bcba5dcbad565076f..321dcaaae7caa0ef76ae947c2dd71bc2f2d7bd85 100644
--- a/src/image/SkImage_Base.h
+++ b/src/image/SkImage_Base.h
@@ -15,6 +15,7 @@
 #include <new>
 
 class GrTextureParams;
+class SkImageCacherator;
 
 enum {
     kNeedNewImageUniqueID = 0
@@ -32,6 +33,7 @@ public:
                               int srcX, int srcY, CachingHint) const;
 
     virtual GrTexture* peekTexture() const { return nullptr; }
+    virtual SkImageCacherator* peekCacherator() const { return nullptr; }
 
     // return a read-only copy of the pixels. We promise to not modify them,
     // but only inspect them (or encode them).