[Code health] Do static_cast in ApplyStandardPropertyValue

Currently at ApplyStandardPropertyValue, we give a double to
FontVariationAxis which is supposed to take a float, and this could cause
float-cast-overflow in corner cases.

This CL does static_cast on the double value before given that to the
FontVariationAxis.

Bug: 900493
Change-Id: Ia4cc4b97bd81296ea1721affead42a2f482b58c0
Reviewed-on: https://chromium-review.googlesource.com/c/1309879Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604292}

third_party/blink/renderer/core/animation/css_font_variation_settings_interpolation_type.cc

@@ -212,7 +212,8 @@ void CSSFontVariationSettingsInterpolationType::ApplyStandardPropertyValue(
   wtf_size_t length = numbers.length();
   for (wtf_size_t i = 0; i < length; ++i) {
     settings->Append(FontVariationAxis(
-        tags[i], ToInterpolableNumber(numbers.Get(i))->Value()));
+        tags[i],
+        static_cast<float>(ToInterpolableNumber(numbers.Get(i))->Value())));
   }
   state.GetFontBuilder().SetVariationSettings(settings);
 }