Follow ARIA spec guidelines for role=button with aria-pressed.

content/browser/accessibility/browser_accessibility_cocoa.mm

Index: content/browser/accessibility/browser_accessibility_cocoa.mm
diff --git a/content/browser/accessibility/browser_accessibility_cocoa.mm b/content/browser/accessibility/browser_accessibility_cocoa.mm
index cfc924bb2df5befe14af22d426f37c5d1638fec1..3566d396c9dce014d2f86822e5f3680e33b4b5b1 100644
--- a/content/browser/accessibility/browser_accessibility_cocoa.mm
+++ b/content/browser/accessibility/browser_accessibility_cocoa.mm
@@ -148,7 +148,7 @@ RoleMap BuildRoleMap() {
     { ui::AX_ROLE_TEXT_AREA, NSAccessibilityTextAreaRole },
     { ui::AX_ROLE_TEXT_FIELD, NSAccessibilityTextFieldRole },
     { ui::AX_ROLE_TIMER, NSAccessibilityGroupRole },
-    { ui::AX_ROLE_TOGGLE_BUTTON, NSAccessibilityButtonRole },
+    { ui::AX_ROLE_TOGGLE_BUTTON, NSAccessibilityCheckBoxRole },
     { ui::AX_ROLE_TOOLBAR, NSAccessibilityToolbarRole },
     { ui::AX_ROLE_TOOLTIP, NSAccessibilityGroupRole },
     { ui::AX_ROLE_TREE, NSAccessibilityOutlineRole },
@@ -206,6 +206,7 @@ RoleMap BuildSubroleMap() {
     { ui::AX_ROLE_STATUS, @"AXApplicationStatus" },
     { ui::AX_ROLE_TAB_PANEL, @"AXTabPanel" },
     { ui::AX_ROLE_TIMER, @"AXApplicationTimer" },
+    { ui::AX_ROLE_TOGGLE_BUTTON, @"AXToggleButton" },
     { ui::AX_ROLE_TOOLTIP, @"AXUserInterfaceTooltip" },
     { ui::AX_ROLE_TREE_ITEM, NSAccessibilityOutlineRowSubrole },
   };
@@ -663,6 +664,17 @@ NSDictionary* attributeToMethodNameMap = nil;
           ui::AX_ATTR_CANVAS_HAS_FALLBACK)) {
     return NSAccessibilityGroupRole;
   }
+  if (role == ui::AX_ROLE_BUTTON) {
+    bool is_aria_pressed_defined;

[dmazzoni, 2014/03/06 06:09:09]

Nit: Obj-C files use camelCase for local variables.

[aboxhall, 2014/03/06 17:45:58]

Done.

+    bool is_mixed;
+    browserAccessibility_->GetAriaTristate("aria-pressed",
+                                           &is_aria_pressed_defined,
+                                           &is_mixed);
+    if (is_aria_pressed_defined)
+      return NSAccessibilityCheckBoxRole;
+    else
+      return NSAccessibilityButtonRole;
+  }
   return NativeRoleFromAXRole(role);
 }
 
@@ -710,6 +722,9 @@ NSDictionary* attributeToMethodNameMap = nil;
     // This control is similar to what VoiceOver calls a "stepper".
     return base::SysUTF16ToNSString(content_client->GetLocalizedString(
         IDS_AX_ROLE_STEPPER));
+  case ui::AX_ROLE_TOGGLE_BUTTON:
+    return base::SysUTF16ToNSString(content_client->GetLocalizedString(
+        IDS_AX_ROLE_TOGGLE_BUTTON));
   default:
     break;
   }
@@ -876,6 +891,18 @@ NSDictionary* attributeToMethodNameMap = nil;
       value = 2;
     }
     return [NSNumber numberWithInt:value];
+  } else if ([self internalRole] == ui::AX_ROLE_TOGGLE_BUTTON) {
+    int value = 0;
+    bool aria_pressed_defined;
+    bool aria_pressed_mixed;
+    value = browserAccessibility_->GetAriaTristate(
+        "aria-pressed", &aria_pressed_defined, &aria_pressed_mixed) ? 1 : 0;
+
+    if (aria_pressed_mixed)
+      value = 2;
+
+    return [NSNumber numberWithInt:value];
+
   } else if ([role isEqualToString:NSAccessibilityProgressIndicatorRole] ||
              [role isEqualToString:NSAccessibilitySliderRole] ||
              [role isEqualToString:NSAccessibilityScrollBarRole]) {