Added an accessibility role of titlebar to labels that are used as window titles

Makes our implementation more similar to native dialogs on Windows, like the Run dialog.

R=dmazzoni@chromium.org, sadrul@chromium.org

Bug: 779297
Change-Id: Idde84c1664f4cc7af43b6470825ff4cdc3ddd475
Tested: Using Inspect tool from the Windows SDK
Reviewed-on: https://chromium-review.googlesource.com/902842Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536715}

ui/accessibility/platform/ax_platform_node_mac.mm

@@ -143,6 +143,7 @@ RoleMap BuildRoleMap() {
       {ax::mojom::Role::kTextFieldWithComboBox, NSAccessibilityComboBoxRole},
       {ax::mojom::Role::kTime, NSAccessibilityGroupRole},
       {ax::mojom::Role::kTimer, NSAccessibilityGroupRole},
+      {ax::mojom::Role::kTitleBar, NSAccessibilityStaticTextRole},
       {ax::mojom::Role::kToggleButton, NSAccessibilityCheckBoxRole},
       {ax::mojom::Role::kToolbar, NSAccessibilityToolbarRole},
       {ax::mojom::Role::kTooltip, NSAccessibilityGroupRole},
@@ -885,6 +886,7 @@ bool IsNameExposedInAXValueForRole(ax::mojom::Role role) {
     case ax::mojom::Role::kListMarker:
     case ax::mojom::Role::kMenuListOption:
     case ax::mojom::Role::kStaticText:
+    case ax::mojom::Role::kTitleBar:
       return true;
     default:
       return false;

ui/accessibility/platform/ax_platform_node_win.cc

@@ -2689,6 +2689,9 @@ int AXPlatformNodeWin::MSAARole() {
     case ax::mojom::Role::kTerm:
       return ROLE_SYSTEM_LISTITEM;
 
+    case ax::mojom::Role::kTitleBar:
+      return ROLE_SYSTEM_TITLEBAR;
+
     case ax::mojom::Role::kToggleButton:
       return ROLE_SYSTEM_PUSHBUTTON;
 
@@ -2755,7 +2758,6 @@ int AXPlatformNodeWin::MSAARole() {
     case ax::mojom::Role::kPresentational:
     case ax::mojom::Role::kSliderThumb:
     case ax::mojom::Role::kSwitch:
-    case ax::mojom::Role::kTitleBar:
     case ax::mojom::Role::kUnknown:
     case ax::mojom::Role::kWebView:
       return ROLE_SYSTEM_CLIENT;

ui/views/controls/label.cc

@@ -406,7 +406,11 @@ WordLookupClient* Label::GetWordLookupClient() {
 }
 
 void Label::GetAccessibleNodeData(ui::AXNodeData* node_data) {
-  node_data->role = ax::mojom::Role::kStaticText;
+  if (text_context_ == style::CONTEXT_DIALOG_TITLE)
+    node_data->role = ax::mojom::Role::kTitleBar;
+  else
+    node_data->role = ax::mojom::Role::kStaticText;
+
   node_data->SetName(full_text_->GetDisplayText());
 }
 

ui/views/widget/native_widget_mac_accessibility_unittest.mm

@@ -871,6 +871,21 @@ TEST_F(NativeWidgetMacAccessibilityTest, Label) {
   // TODO(tapted): Add a test for multiline Labels (currently not supported).
 }
 
+// Labels used as title bars should be exposed as normal static text on Mac.
+TEST_F(NativeWidgetMacAccessibilityTest, LabelUsedAsTitleBar) {
+  Label* label = new Label(base::SysNSStringToUTF16(kTestStringValue),
+                           style::CONTEXT_DIALOG_TITLE, style::STYLE_PRIMARY);
+  label->SetSize(GetWidgetBounds().size());
+  widget()->GetContentsView()->AddChildView(label);
+
+  // Get the Label's accessibility object.
+  id ax_node = A11yElementAtMidpoint();
+  EXPECT_TRUE(ax_node);
+
+  EXPECT_NSEQ(NSAccessibilityStaticTextRole, AXRoleString());
+  EXPECT_NSEQ(kTestStringValue, AXValue());
+}
+
 class TestComboboxModel : public ui::ComboboxModel {
  public:
   TestComboboxModel() = default;