Set default accessibility action for PDF links.

PDF links must have the same default action for accessibility purposes
as HTML links.

Bug: 1400964
Change-Id: I4c086d4cb8ff7ecc3666609aaa4d9c42cb891e49
AX-relnotes: PDF links expose a default action.
Cq-Include-Trybots: luci.chromium.try:fuchsia-arm64-rel,linux-blink-web-tests-force-accessibility-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4120577
Commit-Queue: Jacobo Aragunde Pérez <jaragunde@igalia.com>
Reviewed-by: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1096692}
diff --git a/chrome/browser/pdf/pdf_extension_test.cc b/chrome/browser/pdf/pdf_extension_test.cc
index ddfefc9a..d0a8c6e 100644
--- a/chrome/browser/pdf/pdf_extension_test.cc
+++ b/chrome/browser/pdf/pdf_extension_test.cc
@@ -4381,6 +4381,8 @@
   ASSERT_TRUE(link_node);
 
   // Invoke action on a link and wait for navigation to complete.
+  EXPECT_EQ(ax::mojom::DefaultActionVerb::kJump,
+            link_node->GetData().GetDefaultActionVerb());
   content::AccessibilityNotificationWaiter event_waiter(
       GetActiveWebContents(), ui::kAXModeComplete,
       ax::mojom::Event::kLoadComplete);
diff --git a/components/pdf/renderer/pdf_accessibility_tree.cc b/components/pdf/renderer/pdf_accessibility_tree.cc
index 7385fb2f..d47c9beb 100644
--- a/components/pdf/renderer/pdf_accessibility_tree.cc
+++ b/components/pdf/renderer/pdf_accessibility_tree.cc
@@ -703,6 +703,7 @@
     link_node->AddStringAttribute(ax::mojom::StringAttribute::kName,
                                   std::string());
     link_node->relative_bounds.bounds = link.bounds;
+    link_node->SetDefaultActionVerb(ax::mojom::DefaultActionVerb::kJump);
     node_id_to_annotation_info_->emplace(
         link_node->id,
         PdfAccessibilityTree::AnnotationInfo(page_index_, link.index_in_page));