Remove (trivially) unneeded ImageResourceContent::IntrinsicSize calls

Since SVGImage is handled explicitly already, and we pass
kDoNotRespectImageOrientation to IntrinsicSize() in these functions,
just call Image::Size() directly rather than passing through the
ImageResourceContent method.

Bug: 773272
Change-Id: I6b7c24f5be425f04cd2f68cbc4612054b635bc2b
Reviewed-on: https://chromium-review.googlesource.com/1032745Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#554763}

third_party/blink/renderer/core/style/style_fetched_image.cc

@@ -93,7 +93,7 @@ FloatSize StyleFetchedImage::ImageSize(
   // border-image, etc.)
   //
   // https://drafts.csswg.org/css-images-3/#the-image-orientation
-  FloatSize size(image_->IntrinsicSize(kDoNotRespectImageOrientation));
+  FloatSize size(image->Size());
   return ApplyZoom(size, multiplier);
 }
 

third_party/blink/renderer/core/style/style_fetched_image_set.cc

@@ -94,8 +94,7 @@ FloatSize StyleFetchedImageSet::ImageSize(
   // border-image, etc.)
   //
   // https://drafts.csswg.org/css-images-3/#the-image-orientation
-  FloatSize natural_size(
-      best_fit_image_->IntrinsicSize(kDoNotRespectImageOrientation));
+  FloatSize natural_size(image->Size());
   FloatSize scaled_image_size(ApplyZoom(natural_size, multiplier));
   scaled_image_size.Scale(1 / image_scale_factor_);
   return scaled_image_size;