Revert LoadPendingResources removals.

This is a revert of [1] which causes at least one of potentially several
missing image resources updates on Chrome internal pages. I have not
been able to reduce these pages and understand how MatchedPropertiesCache
is involved here. I have confirmed that this fixes the issue on
chrome://downloads.

This flag was necessary to reproduce issue 1094185:

  --disable-blink-features=CSSMatchedPropertiesCacheDependencies

[1] https://crrev.com/bd57436c85636c1ff62fc83f0deca55282437c0a

Bug: 1094185
Change-Id: I90c4660b5cd4aa095c072033d23bdf3304e3a48d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2252799Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780223}

third_party/blink/renderer/core/css/resolver/style_resolver.cc

@@ -1467,6 +1467,9 @@ bool StyleResolver::ApplyAnimatedStandardProperties(
                                                           standard_transitions);
   }
 
+  // Start loading resources used by animations.
+  state.LoadPendingResources();
+
   DCHECK(!state.GetFontBuilder().FontDirty());
 
   return true;
@@ -1908,12 +1911,12 @@ void StyleResolver::MaybeAddToMatchedPropertiesCache(
     StyleResolverState& state,
     const CacheSuccess& cache_success,
     const MatchResult& match_result) {
+  state.LoadPendingResources();
   if (!state.IsAnimatingCustomProperties() &&
       !cache_success.cached_matched_properties && cache_success.key.IsValid() &&
       MatchedPropertiesCache::IsCacheable(state)) {
     INCREMENT_STYLE_STATS_COUNTER(GetDocument().GetStyleEngine(),
                                   matched_property_cache_added, 1);
-    state.LoadPendingResources();
     matched_properties_cache_.Add(cache_success.key, *state.Style(),
                                   *state.ParentStyle(), state.Dependencies());
   }