Update from https://crrev.com/306655

net/http/transport_security_state.cc

Index: net/http/transport_security_state.cc
diff --git a/net/http/transport_security_state.cc b/net/http/transport_security_state.cc
index 6217d579b5d779d46bc5837ac4ba15676475dd81..a2d377e38813a365312823f4eea6e4d93042f605 100644
--- a/net/http/transport_security_state.cc
+++ b/net/http/transport_security_state.cc
@@ -264,7 +264,7 @@ std::string TransportSecurityState::CanonicalizeHost(const std::string& host) {
       break;
 
     for (size_t j = 0; j < label_length; ++j) {
-      new_host[i + 1 + j] = tolower(new_host[i + 1 + j]);
+      new_host[i + 1 + j] = static_cast<char>(tolower(new_host[i + 1 + j]));
     }
   }