Use newImageSnapshot() to get an image from a Canvas

Source/platform/graphics/ImageBuffer.cpp

Index: Source/platform/graphics/ImageBuffer.cpp
diff --git a/Source/platform/graphics/ImageBuffer.cpp b/Source/platform/graphics/ImageBuffer.cpp
index 73341c56f9f28ce9896ade7cf20ea6935ca78d18..5dfb1cf1a4491285507cf33a39445a7163c3a68e 100644
--- a/Source/platform/graphics/ImageBuffer.cpp
+++ b/Source/platform/graphics/ImageBuffer.cpp
@@ -138,6 +138,11 @@ void ImageBuffer::notifySurfaceInvalid()
         m_client->notifySurfaceInvalid();
 }
 
+PassRefPtr<SkImage> ImageBuffer::newImageSnapshot() const
+{
+    return m_surface->newImageSnapshot();
+}
+
 static SkBitmap deepSkBitmapCopy(const SkBitmap& bitmap)
 {
     SkBitmap tmp;