Add SkImage factory method that forces image to be resolved to a texture.

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 "GrCaps.h"
 #include "GrContext.h"
 #include "GrDrawContext.h"
@@ skipping 264 matching lines @@
     if (!drawContext) {
         return nullptr;
     }
 
     drawContext->drawRect(GrClip::WideOpen(), paint, SkMatrix::I(), rect);
     ctx->flushSurfaceWrites(dst);
     return new SkImage_Gpu(dstDesc.fWidth, dstDesc.fHeight, kNeedNewImageUniqueID,
                            kOpaque_SkAlphaType, dst, budgeted);
 }
 
+static SkImage* create_image_from_maker(GrTextureMaker* maker, SkAlphaType at, uint32_t id) {
+    SkAutoTUnref<GrTexture> texture(maker->refTextureForParams(GrTextureParams::ClampNoFilter()));
+    if (!texture) {
+        return nullptr;
+    }
+    return new SkImage_Gpu(texture->width(), texture->height(), id, at, texture,
+                           SkSurface::kNo_Budgeted);
+}
+
+SkImage* SkImage::newTextureImage(GrContext *context) const {
+    if (!context) {
+        return nullptr;
+    }
+    if (GrTexture* peek = as_IB(this)->peekTexture()) {
+        return peek->getContext() == context ? SkRef(const_cast<SkImage*>(this)) : nullptr;
+    }
+    // No way to check whether a image is premul or not?
+    SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+
+    if (SkImageCacherator* cacher = as_IB(this)->peekCacherator()) {
+        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;
+    }
+    GrBitmapTextureMaker maker(context, bmp);
+    return create_image_from_maker(&maker, at, this->uniqueID());
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 GrTexture* GrDeepCopyTexture(GrTexture* src, bool budgeted) {
     GrContext* ctx = src->getContext();
 
     GrSurfaceDesc desc = src->desc();
     GrTexture* dst = ctx->textureProvider()->createTexture(desc, budgeted, nullptr, 0);
     if (!dst) {
         return nullptr;
     }
 
     const SkIRect srcR = SkIRect::MakeWH(desc.fWidth, desc.fHeight);
     const SkIPoint dstP = SkIPoint::Make(0, 0);
     ctx->copySurface(dst, src, srcR, dstP, GrContext::kFlushWrites_PixelOp);
     return dst;
 }