Add a function to convert a texture backed SkImage to raster.

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 "SkAutoPixmapStorage.h"
 #include "GrCaps.h"
 #include "GrContext.h"
@@ skipping 314 matching lines @@
         return create_image_from_maker(&maker, at, this->uniqueID());
     }
     SkBitmap bmp;
     if (!this->asLegacyBitmap(&bmp, kRO_LegacyBitmapMode)) {
         return nullptr;
     }
     GrBitmapTextureMaker maker(context, bmp);
     return create_image_from_maker(&maker, at, this->uniqueID());
 }
 
+sk_sp<SkImage> SkImage::makeNonTextureImage() const {
+    GrTexture* texture = as_IB(this)->peekTexture();
+    if (!texture) {
+        return sk_ref_sp(const_cast<SkImage*>(this));
+    }
+    SkColorType ct;
+    sk_sp<SkColorSpace> cs;
+    if (!GrPixelConfigToColorAndColorSpace(texture->config(), &ct, &cs)) {
+        return nullptr;
+    }
+    SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+    auto info = SkImageInfo::Make(this->width(), this->height(), ct, at, cs);
+    size_t rowBytes = info.minRowBytes();
+    size_t size = info.getSafeSize(rowBytes);
+    auto data = SkData::MakeUninitialized(size);
+    if (!data) {
+        return nullptr;
+    }
+    SkPixmap pm(info, data->writable_data(), rowBytes);
+    if (!this->readPixels(pm, 0, 0, kDisallow_CachingHint)) {
+        return nullptr;
+    }
+    return MakeRasterData(info, data, rowBytes);
+}
+
 sk_sp<SkImage> SkImage::MakeTextureFromPixmap(GrContext* ctx, const SkPixmap& pixmap,
                                               SkBudgeted budgeted) {
     if (!ctx) {
         return nullptr;
     }
     SkAutoTUnref<GrTexture> texture(GrUploadPixmapToTexture(ctx, pixmap, budgeted));
     if (!texture) {
         return nullptr;
     }
     return sk_make_sp<SkImage_Gpu>(texture->width(), texture->height(), kNeedNewImageUniqueID,
@@ skipping 190 matching lines @@
     if (!ctx) {
         return nullptr;
     }
     SkAutoTUnref<GrTexture> texture(GrUploadMipMapToTexture(ctx, info, texels, mipLevelCount));
     if (!texture) {
         return nullptr;
     }
     return sk_make_sp<SkImage_Gpu>(texture->width(), texture->height(), kNeedNewImageUniqueID,
                                    info.alphaType(), texture, budgeted);
 }