Add support and enable out-of-Blink CORS (fixes issue #2716)

It can still be disabled for a short time by passing
`--disable-features=OutOfBlinkCors` on the command-line.

libcef/common/alloy/alloy_main_delegate.cc

@@ -244,12 +244,6 @@ bool AlloyMainDelegate::BasicStartupComplete(int* exit_code) {
 
     std::vector<std::string> disable_features;
 
-    if (network::features::kOutOfBlinkCors.default_state ==
-        base::FEATURE_ENABLED_BY_DEFAULT) {
-      // TODO: Add support for out-of-Blink CORS (see issue #2716)
-      disable_features.push_back(network::features::kOutOfBlinkCors.name);
-    }
-
 #if defined(OS_WIN)
     if (features::kCalculateNativeWinOcclusion.default_state ==
         base::FEATURE_ENABLED_BY_DEFAULT) {

libcef/common/net/scheme_registration.cc

@@ -8,6 +8,7 @@
 #include "libcef/common/net/scheme_info.h"
 #include "libcef/features/runtime.h"
 
+#include "base/stl_util.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/constants.h"
 #include "net/net_buildflags.h"
@@ -86,4 +87,10 @@ bool IsStandardScheme(const std::string& scheme) {
   return url::IsStandard(scheme.c_str(), scheme_comp);
 }
 
+// Should return the same value as SecurityOrigin::isLocal and
+// SchemeRegistry::shouldTreatURLSchemeAsCorsEnabled.
+bool IsCorsEnabledScheme(const std::string& scheme) {
+  return base::Contains(url::GetCorsEnabledSchemes(), scheme);
+}
+
 }  // namespace scheme

libcef/common/net/scheme_registration.h

@@ -22,6 +22,9 @@ bool IsInternalHandledScheme(const std::string& scheme);
 // Returns true if the specified |scheme| is a registered standard scheme.
 bool IsStandardScheme(const std::string& scheme);
 
+// Returns true if the specified |scheme| is a registered CORS enabled scheme.
+bool IsCorsEnabledScheme(const std::string& scheme);
+
 }  // namespace scheme
 
 #endif  // CEF_LIBCEF_COMMON_NET_SCHEME_REGISTRATION_H_