Fix float-cast overflow in css_color_interpolation_type.cc

This is due to implicit cast from double to int, add static_cast would
fix it.

Bug: 904333
Change-Id: I91a5120e67cd5e2eab7d0ea373b826cc3cbff104
Reviewed-on: https://chromium-review.googlesource.com/c/1350331Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611161}

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

@@ -159,8 +159,10 @@ Color CSSColorInterpolationType::ResolveInterpolableColor(
   if (alpha == 0)
     return Color::kTransparent;
 
-  return MakeRGBA(round(red / alpha), round(green / alpha), round(blue / alpha),
-                  round(alpha));
+  return MakeRGBA(static_cast<int>(round(red / alpha)),
+                  static_cast<int>(round(green / alpha)),
+                  static_cast<int>(round(blue / alpha)),
+                  static_cast<int>(round(alpha)));
 }
 
 class InheritedColorChecker