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

third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp

Index: third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp
diff --git a/third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp b/third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp
index 0864fb2effcaedb0cfae82fa01314a5861b9de23..b567ce3ffbb925e931df3c9454c768b32d2a5fcd 100644
--- a/third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp
+++ b/third_party/WebKit/Source/platform/weborigin/SecurityOrigin.cpp
@@ -103,11 +103,7 @@ static bool shouldTreatAsUniqueOrigin(const KURL& url) {
       (relevantURL.protocolIsInHTTPFamily() || relevantURL.protocolIs("ftp")) &&
       relevantURL.host().isEmpty()));
 
-  // SchemeRegistry needs a lower case protocol because it uses HashMaps
-  // that assume the scheme has already been canonicalized.
-  String protocol = relevantURL.protocol().lower();
-
-  if (SchemeRegistry::shouldTreatURLSchemeAsNoAccess(protocol))
+  if (SchemeRegistry::shouldTreatURLSchemeAsNoAccess(relevantURL.protocol()))
     return true;
 
   // This is the common case.
@@ -115,9 +111,8 @@ static bool shouldTreatAsUniqueOrigin(const KURL& url) {
 }
 
 SecurityOrigin::SecurityOrigin(const KURL& url)
-    : m_protocol(url.protocol().isNull() ? emptyString()
-                                         : url.protocol().lower()),
-      m_host(url.host().isNull() ? emptyString() : url.host().lower()),
+    : m_protocol(url.protocol()),
+      m_host(url.host().lower()),

[brettw, 2016/10/26 01:54:27]

Since you're here, you can delete this lower() call on the host for the same
reason.

[Charlie Harrison, 2016/10/26 01:58:32]

Actually, I tried that and hit a DCHECK failure in this case:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/web/tests/Fram...

I added a similar DCHECK_EQ(host(), host().lower()) that failed because the %3E 
changed %3e. This is after changing the constructor to KURL(KURL(),
"http://f--.com-->").

       m_port(url.port()),
       m_effectivePort(url.port() ? url.port()
                                  : defaultPortForProtocol(m_protocol)),
@@ -126,6 +121,11 @@ SecurityOrigin::SecurityOrigin(const KURL& url)
       m_domainWasSetInDOM(false),
       m_blockLocalAccessFromLocalOrigin(false),
       m_isUniqueOriginPotentiallyTrustworthy(false) {
+  if (m_protocol.isNull())
+    m_protocol = emptyString();
+  if (m_host.isNull())
+    m_host = emptyString();
+
   // Suborigins are serialized into the host, so extract it if necessary.
   String suboriginName;
   if (deserializeSuboriginAndProtocolAndHost(m_protocol, m_host, suboriginName,
@@ -320,8 +320,7 @@ bool SecurityOrigin::canDisplay(const KURL& url) const {
   if (m_universalAccess)
     return true;
 
-  String protocol = url.protocol().lower();
-
+  String protocol = url.protocol();
   if (SchemeRegistry::canDisplayOnlyIfCanRequest(protocol))
     return canRequest(url);