Remove ImageBitmap ColorSpaceInfoUpdate

ImageBitmap's ColorSpaceInfoUpdate enum is not used in the code base
and can be removed.

TBR=junov@chromium.org

Bug: 850985
Change-Id: I3991d33555aeb5bf4375220676254e9e673495c0
Reviewed-on: https://chromium-review.googlesource.com/1093172Reviewed-by: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Commit-Queue: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566024}

third_party/blink/renderer/core/imagebitmap/image_bitmap.h

@@ -27,11 +27,6 @@ class ImageData;
 class ImageDecoder;
 class OffscreenCanvas;
 
-enum ColorSpaceInfoUpdate {
-  kUpdateColorSpaceInformation,
-  kDontUpdateColorSpaceInformation,
-};
-
 class CORE_EXPORT ImageBitmap final : public ScriptWrappable,
                                       public CanvasImageSource,
                                       public ImageBitmapSource {