Revert of Revert[2] of add ImageShader, sharing code with its Bitmap cousin

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 "SkBitmapCache.h"
 #include "SkImage_Gpu.h"
-#include "GrCaps.h"
 #include "GrContext.h"
 #include "GrDrawContext.h"
 #include "effects/GrYUVtoRGBEffect.h"
 #include "SkCanvas.h"
 #include "SkGpuDevice.h"
 #include "SkPixelRef.h"
 
 SkImage_Gpu::SkImage_Gpu(int w, int h, uint32_t uniqueID, SkAlphaType at, GrTexture* tex,
                          SkSurface::Budgeted budgeted)
     : INHERITED(w, h, uniqueID, nullptr)
     , fTexture(SkRef(tex))
     , fAlphaType(at)
     , fBudgeted(budgeted)
     , fAddedRasterVersionToCache(false)
     {}
 
 SkImage_Gpu::~SkImage_Gpu() {
     if (fAddedRasterVersionToCache.load()) {
         SkNotifyBitmapGenIDIsStale(this->uniqueID());
     }
 }
 
 extern void SkTextureImageApplyBudgetedDecision(SkImage* image) {
     if (as_IB(image)->getTexture()) {
         ((SkImage_Gpu*)image)->applyBudgetDecision();
     }
 }
 
+SkShader* SkImage_Gpu::onNewShader(SkShader::TileMode tileX, SkShader::TileMode tileY,
+                                   const SkMatrix* localMatrix) const {
+    SkBitmap bm;
+    GrWrapTextureInBitmap(fTexture, this->width(), this->height(), this->isOpaque(), &bm);
+    return SkShader::CreateBitmapShader(bm, tileX, tileY, localMatrix);
+}
+
 bool SkImage_Gpu::getROPixels(SkBitmap* dst) const {
     if (SkBitmapCache::Find(this->uniqueID(), dst)) {
         SkASSERT(dst->getGenerationID() == this->uniqueID());
         SkASSERT(dst->isImmutable());
         SkASSERT(dst->getPixels());
         return true;
     }
 
     SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
     if (!dst->tryAllocPixels(SkImageInfo::MakeN32(this->width(), this->height(), at))) {
         return false;
     }
     if (!fTexture->readPixels(0, 0, dst->width(), dst->height(), kSkia8888_GrPixelConfig,
                               dst->getPixels(), dst->rowBytes())) {
         return false;
     }
 
     dst->pixelRef()->setImmutableWithID(this->uniqueID());
     SkBitmapCache::Add(this->uniqueID(), *dst);
     fAddedRasterVersionToCache.store(true);
     return true;
 }
 
 GrTexture* SkImage_Gpu::asTextureRef(GrContext* ctx, SkImageUsageType usage) const {
-    const bool is_pow2 = SkIsPow2(this->width()) && SkIsPow2(this->height());
-    const bool npot_tex_supported = ctx->caps()->npotTextureTileSupport();
-    if (!is_pow2 && kUntiled_SkImageUsageType != usage && !npot_tex_supported) {
-        // load as bitmap, since the GPU can support tiling a non-pow2 texture
-        // related to skbug.com/4365
-        SkBitmap bitmap;
-        if (this->getROPixels(&bitmap)) {
-            return GrRefCachedBitmapTexture(ctx, bitmap, usage);
-        } else {
-            return nullptr;
-        }
-    }
-
     fTexture->ref();
     return fTexture;
 }
 
 bool SkImage_Gpu::isOpaque() const {
     return GrPixelConfigIsOpaque(fTexture->config()) || fAlphaType == kOpaque_SkAlphaType;
 }
 
 static void apply_premul(const SkImageInfo& info, void* pixels, size_t rowBytes) {
     switch (info.colorType()) {
@@ skipping 202 matching lines @@
     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;
 }