Revert "MD Extensions - A11y: Announce when an extension has been updated."

This reverts commit 499570b6.

Reason for revert: Caused failures in browser_tests debug builds for
two tests:

CrExtensionsItemsTest.ClickableItems
CrExtensionsItemsTest.FailedReloadFiresLoadError

Original change's description:
> MD Extensions - A11y: Announce when an extension has been updated.
> 
> Bug: 27175
> Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
> Change-Id: I2fed4c16cf0406ea5361413840fe5ab2f5968f69
> Reviewed-on: https://chromium-review.googlesource.com/1003056
> Commit-Queue: Hector Carmona <hcarmona@chromium.org>
> Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#551142}

TBR=rdevlin.cronin@chromium.org,hcarmona@chromium.org

Change-Id: I8f6e654c798127a3a77d0cb2a107443aa8465686
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 27175
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Reviewed-on: https://chromium-review.googlesource.com/1012850Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551284}

chrome/app/md_extensions_strings.grdp

@@ -78,9 +78,6 @@
   <message name="IDS_MD_EXTENSIONS_ITEM_DETAILS" desc="The text on the button to show more details for a given extension.">
     Details
   </message>
-  <message name="IDS_MD_EXTENSIONS_ITEM_RELOAD_DONE" desc="Text used to announce when a single extension has been updated. This is for accessibility.">
-    Extension reloaded
-  </message>
   <message name="IDS_MD_EXTENSIONS_EXTENSION_A11Y_ASSOCIATION" desc="Label used to associate an app or extension with actions a user can take. This label is for screen readers and will only be read out lout. Ex: a button labeled 'Delete' would have the description 'Related to AdBlock'. Without the added description a user on a screen reader would not have context of the extension they want to delete. Note that the action can be 'view details', 'enable', 'delete', 'errors', or something else.">
     Related to <ph name="NAME_PH">$1<ex>AdBlock</ex></ph>
   </message>

chrome/browser/resources/md_extensions/item.js

@@ -186,20 +186,11 @@ cr.define('extensions', function() {
           {page: Page.DETAILS, extensionId: this.data.id});
     },
 
-    /**
-     * @param {Event} e
-     * @private
-     */
-    onReloadTap_: function(e) {
-      this.delegate.reloadItem(this.data.id)
-          .then(
-              () => {
-                Polymer.IronA11yAnnouncer.requestAvailability();
-                this.fire('iron-announce', {text: this.i18n('itemReloadDone')});
-              },
-              loadError => {
-                this.fire('load-error', loadError);
-              });
+    /** @private */
+    onReloadTap_: function() {
+      this.delegate.reloadItem(this.data.id).catch(loadError => {
+        this.fire('load-error', loadError);
+      });
     },
 
     /** @private */

chrome/browser/ui/webui/extensions/extensions_ui.cc

@@ -202,8 +202,6 @@ content::WebUIDataSource* CreateMdExtensionsSource(bool in_dev_mode) {
   source->AddLocalizedString("itemDependentEntry",
                              IDS_MD_EXTENSIONS_DEPENDENT_ENTRY);
   source->AddLocalizedString("itemDetails", IDS_MD_EXTENSIONS_ITEM_DETAILS);
-  source->AddLocalizedString("itemReloadDone",
-                             IDS_MD_EXTENSIONS_ITEM_RELOAD_DONE);
   source->AddLocalizedString("itemErrors", IDS_MD_EXTENSIONS_ITEM_ERRORS);
   source->AddLocalizedString("accessibilityErrorLine",
                              IDS_MD_EXTENSIONS_ACCESSIBILITY_ERROR_LINE);