Handle the "key" field as opposed to keyIdentifier field.

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

Index: third_party/WebKit/Source/core/html/forms/CheckboxInputType.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/CheckboxInputType.cpp b/third_party/WebKit/Source/core/html/forms/CheckboxInputType.cpp
index c8ff788210662e70a6a89d4ee816bcc79c548864..e6ef941095803afefce44c953e82e49cfa4bb0ad 100644
--- a/third_party/WebKit/Source/core/html/forms/CheckboxInputType.cpp
+++ b/third_party/WebKit/Source/core/html/forms/CheckboxInputType.cpp
@@ -61,8 +61,8 @@ String CheckboxInputType::valueMissingText() const
 
 void CheckboxInputType::handleKeyupEvent(KeyboardEvent* event)
 {
-    const String& key = event->keyIdentifier();
-    if (key != "U+0020")
+    const String& key = event->key();
+    if (key != " ")
         return;
     dispatchSimulatedClickIfActive(event);
 }