Expose correct semantics for HTML5 footer element on mac and windows platforms, as per https://bugs…

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 211e954be0ed69d48a01186a8a9a7e20e6f92723..b282cadad3445a35a4738745753558b781084af4 100644
--- a/content/browser/accessibility/browser_accessibility_cocoa.mm
+++ b/content/browser/accessibility/browser_accessibility_cocoa.mm
@@ -118,6 +118,7 @@ RoleMap BuildRoleMap() {
     { WebAccessibility::ROLE_DOCUMENT, NSAccessibilityGroupRole },
     { WebAccessibility::ROLE_DRAWER, NSAccessibilityDrawerRole },
     { WebAccessibility::ROLE_EDITABLE_TEXT, NSAccessibilityTextFieldRole },
+    { WebAccessibility::ROLE_FOOTER, NSAccessibilityGroupRole },
     { WebAccessibility::ROLE_GRID, NSAccessibilityGridRole },
     { WebAccessibility::ROLE_GROUP, NSAccessibilityGroupRole },
     { WebAccessibility::ROLE_GROW_AREA, NSAccessibilityGrowAreaRole },
@@ -222,6 +223,7 @@ RoleMap BuildSubroleMap() {
     { WebAccessibility::ROLE_DEFINITION_LIST_TERM, @"AXTerm" },
     { WebAccessibility::ROLE_DIALOG, @"AXApplicationDialog" },
     { WebAccessibility::ROLE_DOCUMENT, @"AXDocument" },
+    { WebAccessibility::ROLE_FOOTER, @"AXLandmarkContentInfo" },
     { WebAccessibility::ROLE_LANDMARK_APPLICATION, @"AXLandmarkApplication" },
     { WebAccessibility::ROLE_LANDMARK_BANNER, @"AXLandmarkBanner" },
     { WebAccessibility::ROLE_LANDMARK_COMPLEMENTARY,
@@ -553,6 +555,12 @@ NSDictionary* attributeToMethodNameMap = nil;
     }
   }
 
+  if (static_cast<WebAccessibility::Role>( browserAccessibility_->role()) ==
+      WebAccessibility::ROLE_FOOTER) {
+      return base::SysUTF16ToNSString(content_client->GetLocalizedString(
+          IDS_AX_ROLE_FOOTER));
+  }
+
   return NSAccessibilityRoleDescription(role, nil);
 }