detect when we can filter bitmaps/images directly, w/o a tmp layer

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 "GrTextureParamsAdjuster.h"
 #include "effects/GrYUVtoRGBEffect.h"
 #include "SkCanvas.h"
+#include "SkBitmapCache.h"
 #include "SkGpuDevice.h"
+#include "SkGrPixelRef.h"
 #include "SkGrPriv.h"
+#include "SkImageFilter.h"
+#include "SkImage_Gpu.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)
     , fTexture(SkRef(tex))
     , fAlphaType(at)
     , fBudgeted(budgeted)
     , fAddedRasterVersionToCache(false)
 {
@@ skipping 34 matching lines @@
     }
 
     dst->pixelRef()->setImmutableWithID(this->uniqueID());
     if (kAllow_CachingHint == chint) {
         SkBitmapCache::Add(this->uniqueID(), *dst);
         fAddedRasterVersionToCache.store(true);
     }
     return true;
 }
 
+bool SkImage_Gpu::asBitmapForImageFilters(SkBitmap* bitmap) const {
+    bitmap->setInfo(make_info(this->width(), this->height(), this->isOpaque()));
+    bitmap->setPixelRef(new SkGrPixelRef(bitmap->info(), fTexture))->unref();
+    bitmap->pixelRef()->setImmutableWithID(this->uniqueID());
+    return true;
+}
+
 class GpuImage_GrTextureAdjuster : public GrTextureAdjuster {
 public:
     GpuImage_GrTextureAdjuster(const SkImage_Gpu* image)
         : INHERITED(image->peekTexture())
         , fImage(image)
     {}
 
 protected:
     void makeCopyKey(const CopyParams& params, GrUniqueKey* copyKey) override {
         GrUniqueKey baseKey;
@@ skipping 77 matching lines @@
     if (!subTx) {
         return nullptr;
     }
     ctx->copySurface(subTx, fTexture, subset, SkIPoint::Make(0, 0));
     return new SkImage_Gpu(desc.fWidth, desc.fHeight, kNeedNewImageUniqueID, fAlphaType, subTx,
                            fBudgeted);
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-#include "SkGrPixelRef.h"
-#include "SkImageFilter.h"
-
 class SkGpuImageFilterProxy : public SkImageFilter::Proxy {
     GrContext* fCtx;
 
 public:
     SkGpuImageFilterProxy(GrContext* ctx) : fCtx(ctx) {}
 
     SkBaseDevice* createDevice(int width, int height) override {
         GrSurfaceDesc desc;
         desc.fConfig = kSkia8888_GrPixelConfig;
         desc.fFlags = kRenderTarget_GrSurfaceFlag;
@@ skipping 203 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;
 }