Don't call lower() on KURL protocol/host

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 324caf8eb8f7de97b3dda5d1b10fbd2ae0668579..f58bf3d257b9ed4a2890a16af1eb1db10934fa81 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -4379,7 +4379,7 @@ String Document::domain() const {
   return getSecurityOrigin()->domain();
 }
 
-void Document::setDomain(const String& newDomain,
+void Document::setDomain(const String& rawDomain,
                          ExceptionState& exceptionState) {
   UseCounter::count(*this, UseCounter::DocumentSetDomain);
 
@@ -4397,6 +4397,14 @@ void Document::setDomain(const String& newDomain,
     return;
   }
 
+  bool success = false;
+  String newDomain = SecurityOrigin::canonicalizeHost(rawDomain, &success);
+  if (!success) {
+    exceptionState.throwSecurityError("'" + rawDomain +
+                                      "' could not be parsed properly.");

[Mike West, 2016/10/27 07:30:35]

Can you add a layout test that runs through `document.domain` assignments where
this would fail?

+    return;
+  }
+
   if (newDomain.isEmpty()) {
     exceptionState.throwSecurityError("'" + newDomain +
                                       "' is an empty domain.");