Allow canvases to be GPU-accelerated in Workers

third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 441 matching lines @@
     textureInfo.fTarget = GL_TEXTURE_2D;
     textureInfo.fID = textureId;
     GrBackendTextureDesc backendTexture;
     backendTexture.fOrigin = kBottomLeft_GrSurfaceOrigin;
     backendTexture.fWidth = m_size.width();
     backendTexture.fHeight = m_size.height();
     backendTexture.fConfig = kSkia8888_GrPixelConfig;
     backendTexture.fTextureHandle = skia::GrGLTextureInfoToGrBackendObject(textureInfo);
     sk_sp<SkImage> skImage = SkImage::MakeFromAdoptedTexture(grContext, backendTexture);
 
-    // Hold a ref on the GrContext for the texture backing the |skImage|.
-    sk_sp<GrContext> grContextRef = sk_ref_sp(grContext);
     // We reuse the same mailbox name from above since our texture id was consumed from it.
     const auto& skImageMailbox = textureMailbox.mailbox();
     // Use the sync token generated after producing the mailbox. Waiting for this before trying to use
     // the mailbox with some other context will ensure it is valid. We wouldn't need to wait for the
     // consume done in this function because the texture id it generated would only be valid for the
     // DrawingBuffer's context anyways.
     const auto& skImageSyncToken = textureMailbox.sync_token();
 
     // TODO(xidachen): Create a small pool of recycled textures from ImageBitmapRenderingContext's
     // transferFromImageBitmap, and try to use them in DrawingBuffer.
-    return AcceleratedStaticBitmapImage::create(std::move(skImage), grContextRef, skImageMailbox, skImageSyncToken);
+    return AcceleratedStaticBitmapImage::createFromWebGLContextImage(std::move(skImage), skImageMailbox, skImageSyncToken);
 }
 
 DrawingBuffer::TextureParameters DrawingBuffer::chromiumImageTextureParameters()
 {
 #if OS(MACOSX)
     // A CHROMIUM_image backed texture requires a specialized set of parameters
     // on OSX.
     TextureParameters parameters;
     parameters.target = GC3D_TEXTURE_RECTANGLE_ARB;
 
@@ skipping 743 matching lines @@
 
 void DrawingBuffer::restoreTextureBindings()
 {
     // This class potentially modifies the bindings for GL_TEXTURE_2D and
     // GL_TEXTURE_RECTANGLE. Only GL_TEXTURE_2D needs to be restored since
     // the public interface for WebGL does not support GL_TEXTURE_RECTANGLE.
     m_gl->BindTexture(GL_TEXTURE_2D, m_texture2DBinding);
 }
 
 } // namespace blink