ChromeVox: Add keyboard command to announce URL behind link.

This change adds a new ChromeVox keyboard command to announce the
url behind the currently selected link. If no link is selected, the
command does nothing. This change also adds a test to verify correct
behavior.

Bug: 690196.
Change-Id: Iecacb0bcf71657be4c1ea17221ad1f031542b273
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1860482Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708233}

chrome/browser/resources/chromeos/chromevox/chromevox/background/keymaps/next_keymap.json

@@ -1042,6 +1042,15 @@
           "keyCode": [65, 67]
         }
       }
+    },
+     {
+      "command": "readLinkURL",
+      "sequence": {
+        "cvoxModifier": true,
+        "keys": {
+          "keyCode": [65, 76]
+        }
+      }
     }
   ]
 }

chrome/browser/resources/chromeos/chromevox/cvox2/background/background_test.extjs

@@ -2119,3 +2119,21 @@ TEST_F('ChromeVoxBackgroundTest', 'NonModalDialogHeadingJump', function() {
         .replay();
   });
 });
+
+TEST_F('ChromeVoxBackgroundTest', 'ReadLinkURLTest', function() {
+  var mockFeedback = this.createMockFeedback();
+  this.runWithLoadedTree(function() {/*!
+    <a href="https://www.google.com/">A popular link</a>
+    <button>Not a link</button>
+  */}, function(root) {
+    mockFeedback.call(doCmd('nextLink'))
+        .expectSpeech('A popular link', 'Link', 'Press Search+Space to activate.')
+        .call(doCmd('readLinkURL'))
+        .expectSpeech('Link URL: https://www.google.com/')
+        .call(doCmd('nextObject'))
+        .expectSpeech('Not a link', 'Button', 'Press Search+Space to activate.')
+        .call(doCmd('readLinkURL'))
+        .expectSpeech('No URL found')
+        .replay();
+  });
+});

chrome/browser/resources/chromeos/chromevox/cvox2/background/command_handler.js

@@ -971,6 +971,23 @@ CommandHandler.onCommand = function(command) {
         }
       }
       return false;
+    case 'readLinkURL':
+      var node = ChromeVoxState.instance.currentRange.start.node;
+      var rootNode = node.root;
+      while (node && !node.url) {
+        // URL could be an ancestor of current range.
+        node = node.parent;
+      }
+      // Announce node's URL if it's not the root node; we don't want to
+      // announce the URL of the current page.
+      var url = (node && node !== rootNode) ? node.url : '';
+      new Output()
+          .withString(
+              url ? Msgs.getMsg('url_behind_link', [url]) :
+                    Msgs.getMsg('no_url_found'))
+          .withQueueMode(cvox.QueueMode.CATEGORY_FLUSH)
+          .go();
+      return false;
     default:
       return true;
   }

chrome/browser/resources/chromeos/chromevox/strings/chromevox_strings.grd

@@ -3745,6 +3745,9 @@ If you're done with the tutorial, use ChromeVox to navigate to the Close button
       <message desc="Announced when there is no available voice for a language." name="IDS_CHROMEVOX_VOICE_UNAVAILABLE_FOR_LANGUAGE">
         No voice available for language: <ph name="language">$1<ex>English</ex></ph>
       </message>
+      <message desc="Used to describe the link behind a url." name="IDS_CHROMEVOX_URL_BEHIND_LINK">
+        Link URL: <ph name="link_url">$1</ph>
+      </message>
     </messages>
   </release>
 </grit>