Settings: make toggle label for handler default setting clickable

Bug: 749997
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I129f36139b90d9ee1120669e1a510fe0d99fb778
Reviewed-on: https://chromium-review.googlesource.com/1048465Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Esmael El-Moslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557351}

chrome/browser/resources/settings/site_settings/protocol_handlers.html

@@ -24,7 +24,8 @@
       }
     </style>
     <div class="settings-box first two-line">
-      <div id="categoryLabel" class="start">
+      <div id="categoryLabel" class="start" on-click="categoryLabelClicked_"
+          actionable>
         [[computeHandlersDescription_(categoryEnabled)]]
       </div>
       <cr-toggle id="toggle" checked="{{categoryEnabled}}"

chrome/browser/resources/settings/site_settings/protocol_handlers.js

@@ -110,6 +110,11 @@ Polymer({
   },
   // </if>
 
+  /** @private */
+  categoryLabelClicked_: function() {
+    this.$.toggle.click();
+  },
+
   /**
    * Obtains the description for the main toggle.
    * @return {string} The description to use.