[MD Extensions] Don't show the reload spinner for disabled extensions

Don't show the dev-mode reload spinner for disabled extensions. Update
tests to match.

Bug: 769539
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I16927e8faa9c4cbe69042d62b41c93df5ec714b8
Reviewed-on: https://chromium-review.googlesource.com/688682Reviewed-by: Scott Chen <scottchen@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505130}

chrome/browser/resources/md_extensions/item.js

@@ -282,11 +282,11 @@ cr.define('extensions', function() {
      */
     computeDevReloadButtonHidden_: function() {
       // Only display the reload spinner if the extension is unpacked and
-      // not terminated (since if it's terminated, we'll show a crashed reload
-      // buton).
+      // enabled. There's no point in reloading a disabled extension, and we'll
+      // show a crashed reload buton if it's terminated.
       const showIcon =
           this.data.location == chrome.developerPrivate.Location.UNPACKED &&
-          this.data.state != chrome.developerPrivate.ExtensionState.TERMINATED;
+          this.data.state == chrome.developerPrivate.ExtensionState.ENABLED;
       return !showIcon;
     },
 

chrome/test/data/webui/extensions/extension_item_test.js

@@ -110,10 +110,21 @@ cr.define('extension_item_tests', function() {
       testNormalElementsAreVisible(item);
       testDeveloperElementsAreVisible(item);
 
+      // Developer reload button should be visible only for enabled unpacked
+      // extensions.
       extension_test_util.testVisible(item, '#dev-reload-button', false);
+
       item.set('data.location', chrome.developerPrivate.Location.UNPACKED);
       Polymer.dom.flush();
       extension_test_util.testVisible(item, '#dev-reload-button', true);
+
+      item.set('data.state', chrome.developerPrivate.ExtensionState.DISABLED);
+      Polymer.dom.flush();
+      extension_test_util.testVisible(item, '#dev-reload-button', false);
+
+      item.set('data.state', chrome.developerPrivate.ExtensionState.TERMINATED);
+      Polymer.dom.flush();
+      extension_test_util.testVisible(item, '#dev-reload-button', false);
     });
 
     /** Tests that the delegate methods are correctly called. */