[layout] Remove use of DeprecatedByteLengthAsUnsigned

The code there could already deal with size_t, so just use
ByteLengthAsSizeT instead.

R=haraken@chromium.org

Bug: chromium:1008840
Change-Id: I11f6c83b6871ed949c5b1a766a499c3306e12dec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1949800Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721476}

third_party/blink/renderer/core/layout/shapes/shape.cc

@@ -289,7 +289,7 @@ static std::unique_ptr<RasterShapeIntervals> ExtractIntervalsFromImageData(
     const IntRect& margin_rect) {
   DOMArrayBuffer* array_buffer = DOMArrayBuffer::Create(contents);
   DOMUint8ClampedArray* pixel_array = DOMUint8ClampedArray::Create(
-      array_buffer, 0, array_buffer->DeprecatedByteLengthAsUnsigned());
+      array_buffer, 0, array_buffer->ByteLengthAsSizeT());
 
   unsigned pixel_array_offset = 3;  // Each pixel is four bytes: RGBA.
   uint8_t alpha_pixel_threshold = threshold * 255;