Force VoiceOver to use Chrome's computed text for links.

VoiceOver was incorrectly reading links that contained
absolute-positioned text inside. As a workaround, expose
the text of a link in AXDescription instead of AXTitle.
That forces VoiceOver to treat it similarly to a link that
has an aria-label on it, so it favor's Chrome's accessible
text, rather than treating it as a link containing visible
text and using its own (broken) heuristics to describe
what's inside.

It's possible this could have a side effect, if VoiceOver
was announcing more detailed information inside a link.
But it'd still be possible to access the contents of the
link, so this is probably okay.

Bug: 1048782

Change-Id: I2764afe80af1f6afc4c191cf7f98bbcb6b3c025f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2037710
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738791}

content/browser/accessibility/browser_accessibility_cocoa.mm

@@ -1747,6 +1747,10 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
       break;
   }
 
+  // VoiceOver computes the wrong description for a link.
+  if (ui::IsLink(_owner->GetRole()))
+    return true;
+
   // VoiceOver will not read the label of a fieldset or radiogroup unless it is
   // exposed in the description instead of the title.
   switch (_owner->GetRole()) {

content/test/data/accessibility/aria/aria-group-expected-mac.txt

 AXWebArea AXRoleDescription='HTML content'
 ++AXGroup AXRoleDescription='group'
-++++AXLink AXRoleDescription='link' AXTitle='Group Link1'
+++++AXLink AXRoleDescription='link' AXDescription='Group Link1'
 ++++++AXStaticText AXRoleDescription='text' AXValue='Group Link1'
-++++AXLink AXRoleDescription='link' AXTitle='Group Link2'
-++++++AXStaticText AXRoleDescription='text' AXValue='Group Link2'
+++++AXLink AXRoleDescription='link' AXDescription='Group Link2'
+++++++AXStaticText AXRoleDescription='text' AXValue='Group Link2'
\ No newline at end of file

content/test/data/accessibility/aria/aria-link-expected-mac.txt

 AXWebArea AXRoleDescription='HTML content'
-++AXLink AXRoleDescription='link' AXTitle='ARIA Link'
-++++AXStaticText AXRoleDescription='text' AXValue='ARIA Link'
+++AXLink AXRoleDescription='link' AXDescription='ARIA Link'
+++++AXStaticText AXRoleDescription='text' AXValue='ARIA Link'
\ No newline at end of file

content/test/data/accessibility/aria/aria-tree-expected-mac.txt

 AXWebArea
 ++AXOutline AXARIASetSize='2'
 ++++AXRow AXTitle='Animals' AXValue='2' AXARIASetSize='2' AXARIAPosInSet='1'
-++++++AXLink AXTitle='Animals'
+++++++AXLink AXDescription='Animals'
 ++++++++AXStaticText AXValue='Animals'
 ++++++AXGroup AXARIASetSize='2'
 ++++++++AXRow AXTitle='Domesticated' AXARIASetSize='2' AXARIAPosInSet='1'
-++++++++++AXLink AXTitle='Domesticated'
+++++++++++AXLink AXDescription='Domesticated'
 ++++++++++++AXStaticText AXValue='Domesticated'
 ++++++++++AXGroup AXARIASetSize='2'
 ++++++++++++AXRow AXTitle='Dog' AXValue='1' AXARIASetSize='2' AXARIAPosInSet='1'
-++++++++++++++AXLink AXTitle='Dog'
+++++++++++++++AXLink AXDescription='Dog'
 ++++++++++++++++AXStaticText AXValue='Dog'
 ++++++++++++AXRow AXTitle='Cat' AXValue='0' AXARIASetSize='2' AXARIAPosInSet='2'
-++++++++++++++AXLink AXTitle='Cat'
+++++++++++++++AXLink AXDescription='Cat'
 ++++++++++++++++AXStaticText AXValue='Cat'
 ++++++++AXRow AXTitle='Wild' AXARIASetSize='2' AXARIAPosInSet='2'
-++++++++++AXLink AXTitle='Wild'
+++++++++++AXLink AXDescription='Wild'
 ++++++++++++AXStaticText AXValue='Wild'
 ++++AXRow AXTitle='Plants' AXARIASetSize='2' AXARIAPosInSet='2'
-++++++AXLink AXTitle='Plants'
-++++++++AXStaticText AXValue='Plants'
+++++++AXLink AXDescription='Plants'
+++++++++AXStaticText AXValue='Plants'
\ No newline at end of file

content/test/data/accessibility/event/expanded-changed-expected-mac.txt

-AXExpandedChanged on AXLink AXTitle="Toggle"
+AXExpandedChanged on AXLink AXDescription="Toggle"
\ No newline at end of file

content/test/data/accessibility/html/a-expected-mac.txt

 AXWebArea
 ++AXGroup
-++++AXLink AXTitle='normal link'
-++++++AXStaticText AXValue='normal link'
+++++AXLink AXDescription='normal link'
+++++++AXStaticText AXValue='normal link'
\ No newline at end of file

content/test/data/accessibility/html/a-name-expected-mac.txt

 AXWebArea
 ++AXGroup AXTitle='named anchor'
 ++++AXStaticText AXValue='named anchor'
-++AXLink AXTitle='both a named anchor and a link'
-++++AXStaticText AXValue='both a named anchor and a link'
+++AXLink AXDescription='both a named anchor and a link'
+++++AXStaticText AXValue='both a named anchor and a link'
\ No newline at end of file

content/test/data/accessibility/html/a-with-img-expected-mac.txt

 AXWebArea
 ++AXGroup
-++++AXLink AXTitle='Link with image at start.'
+++++AXLink AXDescription='Link with image at start.'
 ++++++AXImage AXDescription='Link'
 ++++++AXStaticText AXValue=' with image at start.'
 ++++AXStaticText AXValue=' '
-++++AXLink AXTitle='Link with image in the middle.'
+++++AXLink AXDescription='Link with image in the middle.'
 ++++++AXStaticText AXValue='Link with '
 ++++++AXImage AXDescription='image'
 ++++++AXStaticText AXValue=' in the middle.'
 ++++AXStaticText AXValue=' '
-++++AXLink AXTitle='Link with broken in the middle.'
+++++AXLink AXDescription='Link with broken in the middle.'
 ++++++AXStaticText AXValue='Link with '
 ++++++AXImage AXDescription='broken'
 ++++++AXStaticText AXValue=' in the middle.'
 ++++AXStaticText AXValue=' '
-++++AXLink AXTitle='Link with image at the end'
+++++AXLink AXDescription='Link with image at the end'
 ++++++AXStaticText AXValue='Link with image at the '
 ++++++AXImage AXDescription='end'
\ No newline at end of file

content/test/data/accessibility/html/canvas-expected-mac.txt

@@ -3,5 +3,5 @@ AXWebArea
 ++++AXGroup
 ++++++AXStaticText AXValue='Static fallback'
 ++++AXGroup
-++++++AXLink AXTitle='Interactive fallback'
-++++++++AXStaticText AXValue='Interactive fallback'
+++++++AXLink AXDescription='Interactive fallback'
+++++++++AXStaticText AXValue='Interactive fallback'
\ No newline at end of file

content/test/data/accessibility/html/img-link-empty-alt-expected-mac.txt

 AXWebArea
 ++AXGroup
-++++AXLink AXTitle='unread '
+++++AXLink AXDescription='unread '
 ++++++AXStaticText AXValue='unread '
-++++AXLink AXTitle='read '
+++++AXLink AXDescription='read '
 ++++++AXStaticText AXValue='read '
-++++AXLink AXTitle='read '
+++++AXLink AXDescription='read '
 ++++++AXStaticText AXValue='read '
-++++AXLink AXTitle='read'
+++++AXLink AXDescription='read'
 ++++++AXImage AXDescription='/read.jpg'
 ++++++AXStaticText AXValue='read'
\ No newline at end of file

content/test/data/accessibility/html/in-page-links-expected-mac.txt

 AXWebArea
-++AXLink AXTitle='Empty anchor' AXLinkedUIElements=["AXGroup"]
+++AXLink AXDescription='Empty anchor' AXLinkedUIElements=["AXGroup"]
 ++++AXStaticText AXValue='Empty anchor'
 ++AXStaticText AXValue=' '
-++AXLink AXTitle='Anchor with content' AXLinkedUIElements=["AXGroup Anchor with content"]
+++AXLink AXDescription='Anchor with content' AXLinkedUIElements=["AXGroup Anchor with content"]
 ++++AXStaticText AXValue='Anchor with content'
 ++AXStaticText AXValue=' '
-++AXLink AXTitle='Anchor with ID' AXLinkedUIElements=["AXGroup Anchor with ID"]
+++AXLink AXDescription='Anchor with ID' AXLinkedUIElements=["AXGroup Anchor with ID"]
 ++++AXStaticText AXValue='Anchor with ID'
 ++AXStaticText AXValue=' '
-++AXLink AXTitle='Empty span' AXLinkedUIElements=["AXGroup"]
+++AXLink AXDescription='Empty span' AXLinkedUIElements=["AXGroup"]
 ++++AXStaticText AXValue='Empty span'
 ++AXStaticText AXValue=' '
-++AXLink AXTitle='Span with content' AXLinkedUIElements=["AXGroup"]
+++AXLink AXDescription='Span with content' AXLinkedUIElements=["AXGroup"]
 ++++AXStaticText AXValue='Span with content'
 ++AXStaticText AXValue=' '
-++AXLink AXTitle='Paragraph with content' AXLinkedUIElements=["AXGroup"]
+++AXLink AXDescription='Paragraph with content' AXLinkedUIElements=["AXGroup"]
 ++++AXStaticText AXValue='Paragraph with content'
 ++AXGroup
 ++++AXGroup
@@ -32,4 +32,4 @@ AXWebArea
 ++++AXGroup
 ++++++AXStaticText AXValue='Span with content'
 ++AXGroup
-++++AXStaticText AXValue='Paragraph with content'
+++++AXStaticText AXValue='Paragraph with content'
\ No newline at end of file

content/test/data/accessibility/html/link-inside-heading-expected-mac.txt

 AXWebArea
 ++AXHeading AXTitle='Link In Heading' AXValue='1'
-++++AXLink AXTitle='Link In Heading'
-++++++AXStaticText AXValue='Link In Heading'
+++++AXLink AXDescription='Link In Heading'
+++++++AXStaticText AXValue='Link In Heading'
\ No newline at end of file

content/test/data/accessibility/html/modal-dialog-opened-expected-mac.txt

@@ -2,5 +2,5 @@ AXWebArea
 ++AXGroup
 ++AXGroup AXSubrole=AXApplicationDialog
 ++++AXStaticText AXValue='The dialog subtree should be the only text content in the accessibility tree. '
-++++AXLink AXTitle='Link inside the dialog.'
-++++++AXStaticText AXValue='Link inside the dialog.'
+++++AXLink AXDescription='Link inside the dialog.'
+++++++AXStaticText AXValue='Link inside the dialog.'
\ No newline at end of file

content/test/data/accessibility/html/navigation-expected-mac.txt

 AXWebArea AXRoleDescription='HTML content'
 ++AXGroup AXSubrole=AXLandmarkNavigation AXRoleDescription='navigation'
-++++AXLink AXRoleDescription='link' AXTitle='Don't click on me'
-++++++AXStaticText AXRoleDescription='text' AXValue='Don't click on me'
+++++AXLink AXRoleDescription='link' AXDescription='Don't click on me'
+++++++AXStaticText AXRoleDescription='text' AXValue='Don't click on me'
\ No newline at end of file

content/test/data/accessibility/html/span-expected-mac.txt

@@ -12,30 +12,30 @@ AXWebArea
 ++AXGroup
 ++++AXStaticText AXValue='E1. Eat'
 ++++AXStaticText AXValue=' '
-++++AXLink
+++++AXLink AXDescription='space'
 ++++++AXStaticText AXValue='space'
 ++AXGroup
 ++++AXStaticText AXValue='E2. Eat'
 ++++AXStaticText AXValue=' '
-++++AXLink
+++++AXLink AXDescription='space'
 ++++++AXStaticText AXValue='space'
 ++AXGroup
 ++++AXStaticText AXValue='E3. Eat'
 ++++AXStaticText AXValue=' '
-++++AXLink
+++++AXLink AXDescription='space'
 ++++++AXStaticText AXValue='space'
 ++AXGroup
-++++AXLink
+++++AXLink AXDescription='E4. Eat'
 ++++++AXStaticText AXValue='E4. Eat'
 ++++AXStaticText AXValue=' '
 ++++AXStaticText AXValue='space'
 ++AXGroup
-++++AXLink
+++++AXLink AXDescription='E5. Eat'
 ++++++AXStaticText AXValue='E5. Eat'
 ++++AXStaticText AXValue=' '
 ++++AXStaticText AXValue='space'
 ++AXGroup
-++++AXLink
+++++AXLink AXDescription='E6. Eat'
 ++++++AXStaticText AXValue='E6. Eat'
 ++++AXStaticText AXValue=' '
 ++++AXStaticText AXValue='space'
@@ -67,4 +67,4 @@ AXWebArea
 ++AXGroup
 ++++AXStaticText AXValue='K8. Keep'
 ++++AXStaticText AXValue=' '
-++++AXStaticText AXValue='space'
+++++AXStaticText AXValue='space'
\ No newline at end of file