The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/936948502c48693965289070e089df54cc32a273

commit 936948502c48693965289070e089df54cc32a273
Author: Fredrik Söderquist <fs@opera.com>
Date: Fri Oct 13 08:38:13 2017

Handle small/zero pixel densities correctly for img.naturalWidth/Height

ImageResourceContent::ImageSize has some special logic for clamping
image dimension that end up as "zero" (LayoutUnits) to one after having
been scaled by the multiplier it is passed.
This "correction" means that for images with a small/zero pixel density,
we'll end up returning 1 even when the density corrected dimension is
(integral) 0.

To handle this, pass 1 as the multiplier to avoid the dimension clamping
and perform the pixel scaling "manually".
While doing this also move the pixel density correction code to
HTMLImageElement, and get rid of the code from ImageResourceContent,
since it only used for <img> naturalWidth/naturalHeight.
This makes ImageResourceContent::SizeType only have a single value, so
remove the enumeration and the argument.

Bug: 773272,  773284 
Change-Id: Ie4a907d6cb7f262c876a5010bb7dd6a92af1cb9a
Reviewed-on: https://chromium-review.googlesource.com/708815
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#508646}
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/LayoutTests/external/wpt/html/semantics/embedded-content/the-img-element/current-pixel-density/basic-expected.txt
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/Source/core/html/HTMLImageElement.cpp
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/Source/core/html/HTMLImageElement.h
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.cpp
[modify] https://crrev.com/936948502c48693965289070e089df54cc32a273/third_party/WebKit/Source/core/loader/resource/ImageResourceContent.h