Low risk nullable => non-nullable change

third_party/WebKit/Source/core/frame/History.idl

Index: third_party/WebKit/Source/core/frame/History.idl
diff --git a/third_party/WebKit/Source/core/frame/History.idl b/third_party/WebKit/Source/core/frame/History.idl
index fef8e1fdbaa62510270b50b6b93da475f753e3eb..e64030876411b7fb09cd88a73b7f63031d865039 100644
--- a/third_party/WebKit/Source/core/frame/History.idl
+++ b/third_party/WebKit/Source/core/frame/History.idl
@@ -37,6 +37,6 @@ interface History {
     [CallWith=ExecutionContext] void forward();
     // TODO(foolip): The SerializedScriptValue types should be any.
     // TODO(foolip): The title arguments should not be nullable.
-    [RaisesException] void pushState(SerializedScriptValue data, DOMString? title, optional DOMString? url = null);
-    [RaisesException] void replaceState(SerializedScriptValue data, DOMString? title, optional DOMString? url = null);
+    [RaisesException] void pushState(SerializedScriptValue data, DOMString title, optional DOMString? url = null);

[foolip, 2016/12/13 22:43:24]

Can you check if the string passed in here ever re-emerges where a script can
see it? If so this change can be tested, passing in null should now behave as
"null" instead of whatever the previous behavior was, "" or null presumably.

[lunalu1, 2016/12/14 11:04:24]

The title is never touched by our code. 

+    [RaisesException] void replaceState(SerializedScriptValue data, DOMString title, optional DOMString? url = null);
 };