Add accessibility label to managed icon.

Managed icon on the setting is read out as
"This setting is managed".

Bug: 878607
Change-Id: I8dcff087f8280fb1c9fdabdb17946c2917f94461
Reviewed-on: https://chromium-review.googlesource.com/1203375Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Vladislav Kuzkokov <vkuzkokov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#588866}

chrome/app/printing_strings.grdp

@@ -306,6 +306,9 @@
     <message name="IDS_PRINT_PREVIEW_RESOLVE_EXTENSION_USB_ERROR_MESSAGE" desc="Message shown to the user when they attempt to select a USB pinter supported by an extension, but for which the extension does not yet have access permission. The message is shown if the user grants the extension access to the USB device (by confirming printer selection), but the extension is not able to retrieve information about the printer, and an error is reported. The message contains a placeholder for the name of the extension.">
       <ph name="EXTENSION_NAME">$1<ex>Print app</ex></ph> could not communicate with this printer. Make sure the printer is plugged in and try again.
     </message>
+    <message name="IDS_PRINT_PREVIEW_MANAGED_OPTION_TEXT" desc="Text shown when hovering over managed setting icon">
+      This setting is managed
+    </message>
     <if expr="chromeos">
       <message name="IDS_PRINT_CONFIGURING_IN_PROGRESS_TEXT" desc="Message shown to user while their printer is being setup in Chrome OS.">
         Setting up

chrome/browser/resources/print_preview/new/settings_section.html

@@ -42,7 +42,8 @@
     </style>
     <slot name="title"></slot>
     <img src="../../../../../ui/webui/resources/images/business.svg"
-         hidden$="[[!managed]]" class="policy-icon">
+         hidden$="[[!managed]]" class="policy-icon"
+         aria-label="$i18n{managedOption}">
     <slot name="controls"></slot>
   </template>
   <script src="settings_section.js"></script>

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

@@ -360,6 +360,8 @@ void AddPrintPreviewStrings(content::WebUIDataSource* source) {
                              IDS_CLOUD_PRINT_REGISTER_PRINTER_INFORMATION);
   source->AddLocalizedString("moreOptionsLabel", IDS_MORE_OPTIONS_LABEL);
   source->AddLocalizedString("lessOptionsLabel", IDS_LESS_OPTIONS_LABEL);
+  source->AddLocalizedString("managedOption",
+                             IDS_PRINT_PREVIEW_MANAGED_OPTION_TEXT);
 #if defined(OS_CHROMEOS)
   source->AddLocalizedString("configuringInProgressText",
                              IDS_PRINT_CONFIGURING_IN_PROGRESS_TEXT);