Remove linear-function easing TypeError exemption.

third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html

Index: third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html
diff --git a/third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html b/third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html
index 29c56676abdc98d02a9bf4a56d1fc88714da2e3d..8a1814c6678cf2aecad43597a2d39968372d7b6d 100644
--- a/third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html
+++ b/third_party/WebKit/LayoutTests/animations/function-easing-use-counters-linear.html
@@ -27,7 +27,9 @@ test(() => {
   // This linear function value is the one expected from uses of the unpatched
   // Web Animations polyfill (i.e. old versions lacking
   // https://github.com/web-animations/web-animations-next/pull/423).
-  document.documentElement.animate([], { easing: 'function (a){return a}' });
+  assert_throws(
+      {name: 'TypeError'},
+      function() { document.documentElement.animate([], { easing: 'function (a){return a}' }) });
   assert_true(internals.isUseCounted(document, WebAnimationsEasingAsFunctionLinear));
   assert_false(internals.isUseCounted(document, WebAnimationsEasingAsFunctionOther));
 }, 'A specific linear function for easing is counted in WebAnimationsEasingAsFunctionLinear.');