[accessiblity] Fix dialog title being vocalized twice

- Adds temporary fix to cr-dialog, to fix dialog title being vocalized
  twice by chromeVOX, this should be reversed when crbug.com/1139958 is
  closed.
- Add vocalization of signal strength icon

Bug: 1007433
Change-Id: I6a1dc2d8d37bc3e7e43097bcf2aa568c280152b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2480884
Commit-Queue: Nnamdi Theodore Johnson-kanu <tjohnsonkanu@google.com>
Reviewed-by: John Lee <johntlee@chromium.org>
Reviewed-by: Regan Hsu <hsuregan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819219}

chrome/browser/resources/settings/chromeos/internet_page/tether_connection_dialog.html

@@ -79,8 +79,7 @@
         <div id="host-device-container">
           <iron-icon id="host-device-signal-strength-icon"
               icon="[[getSignalStrengthIconName_(managedProperties)]]"
-              aria-label$="[[getSignalStrengthLabel_(managedProperties)]]"
-              aria-hidden="true">
+              aria-label$="[[getSignalStrengthLabel_(managedProperties)]]">
           </iron-icon>
           <div id="host-device-text-container">
             <span id="host-device-text-name"

ui/webui/resources/cr_elements/cr_dialog/cr_dialog.html

@@ -145,9 +145,13 @@
         margin-top: 4px;
       }
     </style>
+    <!-- TODO(crbug/1139958): Remove "not chromeos" block when chromeVox issue is fixed-->
+    <!--Update both "not chromeos" and "chromeos" blocks if either changes-->
+<if expr="not chromeos">
     <dialog id="dialog" on-close="onNativeDialogClose_"
-        on-cancel="onNativeDialogCancel_" part="dialog" aria-labelledby="title">
-      <!-- This wrapper is necessary, such that the "pulse" animation is not
+        on-cancel="onNativeDialogCancel_" part="dialog"
+        aria-labelledby="title">
+    <!-- This wrapper is necessary, such that the "pulse" animation is not
         erroneously played when the user clicks on the outer-most scrollbar. -->
       <div id="content-wrapper" part="wrapper">
         <div class="top-container">
@@ -168,6 +172,32 @@
         <slot name="footer"></slot>
       </div>
     </dialog>
+</if>
+<if expr="chromeos">
+    <dialog id="dialog" on-close="onNativeDialogClose_"
+        on-cancel="onNativeDialogCancel_" part="dialog">
+    <!-- This wrapper is necessary, such that the "pulse" animation is not
+        erroneously played when the user clicks on the outer-most scrollbar. -->
+        <div id="content-wrapper" part="wrapper">
+          <div class="top-container">
+            <div id="title" class="title-container" tabindex="-1">
+              <slot name="title"></slot>
+            </div>
+            <cr-icon-button id="close" class="icon-clear"
+                hidden$="[[!showCloseButton]]" aria-label$="[[closeText]]"
+                on-click="cancel" on-keypress="onCloseKeypress_">
+            </cr-icon-button>
+          </div>
+          <slot name="header"></slot>
+          <div class="body-container" id="container" show-bottom-shadow
+              part="body-container">
+            <slot name="body"></slot>
+          </div>
+          <slot name="button-container"></slot>
+          <slot name="footer"></slot>
+        </div>
+    </dialog>
+</if>
   </template>
   <script src="cr_dialog.js"></script>
 </dom-module>

ui/webui/resources/cr_elements_resources.grdp

@@ -54,6 +54,7 @@
              type="chrome_html" />
   <structure name="IDR_CR_ELEMENTS_CR_DIALOG_HTML"
              file="cr_elements/cr_dialog/cr_dialog.html"
+             preprocess="true"
              type="chrome_html" />
   <structure name="IDR_CR_ELEMENTS_CR_DIALOG_JS"
              file="cr_elements/cr_dialog/cr_dialog.js"

ui/webui/resources/cr_elements_resources_v3.grdp

@@ -24,6 +24,7 @@
   <include name="IDR_CR_ELEMENTS_CR_DIALOG_M_JS"
          file="${root_gen_dir}/ui/webui/resources/cr_elements/cr_dialog/cr_dialog.m.js"
          use_base_dir="false"
+         preprocess="true"
          type="BINDATA" />
   <include name="IDR_CR_ELEMENTS_CR_DRAWER_M_JS"
          file="${root_gen_dir}/ui/webui/resources/cr_elements/cr_drawer/cr_drawer.m.js"