Chrome Cleanup: fix non-actionable button due to a line break in handler

on-tap="toggleExpandButton_" had a line break in it, preventing the
handler from being properly registered.

TBR=tommycli@chromium.org

Bug: 690020
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I14ab6338e5c81ef798fa2fce0749999f6e10978d
Reviewed-on: https://chromium-review.googlesource.com/579654Reviewed-by: proberge <proberge@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: proberge <proberge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488278}

chrome/browser/resources/settings/chrome_cleanup_page/chrome_cleanup_page.html

@@ -114,8 +114,8 @@
               on-settings-boolean-control-change="changeLogsPermission_">
       </settings-toggle-button>
     </div>
-    <div id="show-files-button" class="settings-box" actionable on-tap="
-        toggleExpandButton_" hidden="[[!showDetails_]]">
+    <div id="show-files-button" class="settings-box" actionable
+        on-tap="toggleExpandButton_" hidden="[[!showDetails_]]">
       <div class="start">
         $i18n{chromeCleanupLinkShowFiles}
       </div>