[Code Health] Minor clean up in throughput_test_cases/

There are 3 html files under this dir, thhis CL add one space to
clean up the format. No behavior change.

TBR=sadrul@chromium.org

Bug: None
Change-Id: I4854a145ab404dac5689005a9c79372b8af19404
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2041799Reviewed-by: Xida Chen <xidachen@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738980}

chrome/test/data/perf/throughput_test_cases/main-animations-throughput.html

@@ -29,7 +29,7 @@ Press any key to toggle animation.
 <script>
 
 const targetMainFps =
-  window.location.hash.length > 1 ? +window.location.hash.substr(1) : 0;
+  window.location.hash.length > 1 ? + window.location.hash.substr(1) : 0;
 const skipEvery = targetMainFps > 0 ? parseInt(60 / targetMainFps) : 0;
 
 const query = window.location.search.substr(1).split('&');

chrome/test/data/perf/throughput_test_cases/main-impl-animations-no-update-throughput.html

@@ -49,7 +49,7 @@ Press any key to toggle animation.
 <script>
 
 const targetMainFps =
-  window.location.hash.length > 1 ? +window.location.hash.substr(1) : 0;
+  window.location.hash.length > 1 ? + window.location.hash.substr(1) : 0;
 const skipEvery = targetMainFps > 0 ? parseInt(60 / targetMainFps) : 0;
 const shouldJank = window.location.search.indexOf('?jank') >= 0;
 

chrome/test/data/perf/throughput_test_cases/main-impl-animations-throughput.html

@@ -50,7 +50,7 @@ Press any key to toggle animation.
 <script>
 
 const targetMainFps =
-  window.location.hash.length > 1 ? +window.location.hash.substr(1) : 0;
+  window.location.hash.length > 1 ? + window.location.hash.substr(1) : 0;
 const skipEvery = targetMainFps > 0 ? parseInt(60 / targetMainFps) : 0;
 
 var currentValue = 0;