Cherry-pick of https://skia.googlesource.com/skia.git/+/96c118edff293af93db0a2b1b6775428117924b1 to…

src/gpu/SkGrPixelRef.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
@@ skipping 33 matching lines @@
 void SkROLockPixelsPixelRef::onUnlockPixels() {
     fBitmap.unlockPixels();
 }
 
 bool SkROLockPixelsPixelRef::onLockPixelsAreWritable() const {
     return false;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static SkGrPixelRef* copyToTexturePixelRef(GrTexture* texture, SkColorType dstCT,
+static SkGrPixelRef* copy_to_new_texture_pixelref(GrTexture* texture, SkColorType dstCT,
                                            const SkIRect* subset) {
     if (NULL == texture || kUnknown_SkColorType == dstCT) {
         return NULL;
     }
     GrContext* context = texture->getContext();
     if (NULL == context) {
         return NULL;
     }
     GrTextureDesc desc;
 
@@ skipping 14 matching lines @@
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
     desc.fConfig = SkImageInfo2GrPixelConfig(dstCT, kPremul_SkAlphaType);
 
     GrTexture* dst = context->createUncachedTexture(desc, NULL, 0);
     if (NULL == dst) {
         return NULL;
     }
 
     context->copyTexture(texture, dst->asRenderTarget(), topLeft);
 
-    // TODO: figure out if this is responsible for Chrome canvas errors
-#if 0
-    // The render texture we have created (to perform the copy) isn't fully
-    // functional (since it doesn't have a stencil buffer). Release it here
-    // so the caller doesn't try to render to it.
-    // TODO: we can undo this release when dynamic stencil buffer attach/
-    // detach has been implemented
-    dst->releaseRenderTarget();
-#endif
+    // Blink is relying on the above copy being sent to GL immediately in the case when the source
+    // is a WebGL canvas backing store. We could have a TODO to remove this flush, but we have a
+    // larger TODO to remove SkGrPixelRef entirely.
+    context->flush();
 
     SkImageInfo info = SkImageInfo::Make(desc.fWidth, desc.fHeight, dstCT, kPremul_SkAlphaType);
     SkGrPixelRef* pixelRef = SkNEW_ARGS(SkGrPixelRef, (info, dst));
     SkSafeUnref(dst);
     return pixelRef;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkGrPixelRef::SkGrPixelRef(const SkImageInfo& info, GrSurface* surface,
@@ skipping 41 matching lines @@
     if (NULL == fSurface) {
         return NULL;
     }
     
     // Note that when copying a render-target-backed pixel ref, we
     // return a texture-backed pixel ref instead.  This is because
     // render-target pixel refs are usually created in conjunction with
     // a GrTexture owned elsewhere (e.g., SkGpuDevice), and cannot live
     // independently of that texture.  Texture-backed pixel refs, on the other
     // hand, own their GrTextures, and are thus self-contained.
-    return copyToTexturePixelRef(fSurface->asTexture(), dstCT, subset);
+    return copy_to_new_texture_pixelref(fSurface->asTexture(), dstCT, subset);
 }
 
 bool SkGrPixelRef::onReadPixels(SkBitmap* dst, const SkIRect* subset) {
     if (NULL == fSurface || fSurface->wasDestroyed()) {
         return false;
     }
 
     int left, top, width, height;
     if (NULL != subset) {
         left = subset->fLeft;
         width = subset->width();
         top = subset->fTop;
         height = subset->height();
     } else {
         left = 0;
         width = this->info().fWidth;
         top = 0;
         height = this->info().fHeight;
     }
     if (!dst->allocPixels(SkImageInfo::MakeN32Premul(width, height))) {
         SkDebugf("SkGrPixelRef::onReadPixels failed to alloc bitmap for result!\n");
         return false;
     }
     SkAutoLockPixels al(*dst);
     void* buffer = dst->getPixels();
     return fSurface->readPixels(left, top, width, height,
                                 kSkia8888_GrPixelConfig,
                                 buffer, dst->rowBytes());
 }