Allow canvases to be GPU-accelerated in Workers

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

Index: third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
index 296bf56de55d410e15cdfd99629e34b80dfe989d..a003681da3ee3356c7cb7077fa284e2045ac8ebf 100644
--- a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
@@ -459,8 +459,6 @@ PassRefPtr<StaticBitmapImage> DrawingBuffer::transferToStaticBitmapImage()
     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
@@ -471,7 +469,7 @@ PassRefPtr<StaticBitmapImage> DrawingBuffer::transferToStaticBitmapImage()
 
     // 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()