Remove unused SkImage_Base and SkImage_Gpu onNewSurface methods
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2353403002

Review-Url: https://codereview.chromium.org/2353403002
diff --git a/src/image/SkImage_Base.h b/src/image/SkImage_Base.h
index 7ebedeb..b314cc6 100644
--- a/src/image/SkImage_Base.h
+++ b/src/image/SkImage_Base.h
@@ -54,10 +54,6 @@
     // but only inspect them (or encode them).
     virtual bool getROPixels(SkBitmap*, CachingHint = kAllow_CachingHint) const = 0;
 
-    virtual sk_sp<SkSurface> onNewSurface(const SkImageInfo& info) const {
-        return SkSurface::MakeRaster(info);
-    }
-
     // Caller must call unref when they are done.
     virtual GrTexture* asTextureRef(GrContext*, const GrTextureParams&,
                                     SkSourceGammaTreatment) const = 0;
diff --git a/src/image/SkImage_Gpu.h b/src/image/SkImage_Gpu.h
index a9d9c33..02260bc 100644
--- a/src/image/SkImage_Gpu.h
+++ b/src/image/SkImage_Gpu.h
@@ -51,10 +51,6 @@
     bool onReadPixels(const SkImageInfo&, void* dstPixels, size_t dstRowBytes,
                       int srcX, int srcY, CachingHint) const override;
 
-    sk_sp<SkSurface> onNewSurface(const SkImageInfo& info) const override {
-        return SkSurface::MakeRenderTarget(fTexture->getContext(), SkBudgeted::kNo, info);
-    }
-
 private:
     SkAutoTUnref<GrTexture>     fTexture;
     const SkAlphaType           fAlphaType;