Add UseCounters for name attribute matching of <map> and <input type=radio>

third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp

Index: third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp b/third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp
index 8742f4e2487a03e695dc56e1602a3bb7fbcf1c8f..8a9167c7ae27c6485a4b7458a24f49504c3fb583 100644
--- a/third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp
+++ b/third_party/WebKit/Source/core/html/forms/RadioButtonGroupScope.cpp
@@ -232,10 +232,18 @@ void RadioButtonGroupScope::addButton(HTMLInputElement* element)
     if (!m_nameToGroupMap)
         m_nameToGroupMap = new NameToGroupMap;
 
-    Member<RadioButtonGroup>& group = m_nameToGroupMap->add(element->name(), nullptr).storedValue->value;
-    if (!group)
-        group = RadioButtonGroup::create();
-    group->add(element);
+    auto keyValue = m_nameToGroupMap->add(element->name(), nullptr).storedValue;
+    if (!keyValue->value) {
+        keyValue->value = RadioButtonGroup::create();
+    } else {
+        if (keyValue->key == element->name())
+            UseCounter::count(element->document(), UseCounter::RadioNameMatchingStrict);
+        else if (equalIgnoringASCIICase(keyValue->key, element->name()))
+            UseCounter::count(element->document(), UseCounter::RadioNameMatchingASCIICaseless);
+        else
+            UseCounter::count(element->document(), UseCounter::RadioNameMatchingCaseFolding);
+    }
+    keyValue->value->add(element);
 }
 
 void RadioButtonGroupScope::updateCheckedState(HTMLInputElement* element)