Support offscreen contexts which own their backing surface

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index 0c3057a6a95f943ab9154df4298ba7c5a5c17423..97ab33fe0daae6841c6875418804b921dae0ab26 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -259,6 +259,10 @@ const base::Feature kWebRtcUseEchoCanceller3{"WebRtcUseEchoCanceller3",
 // https://wicg.github.io/webusb
 const base::Feature kWebUsb{"WebUSB", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables WebVR experimental rendering optimizations.
+const base::Feature kWebVRExperimentalRendering{
+    "WebVRExperimentalRendering", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Make sendBeacon throw for a Blob with a non simple type.
 const base::Feature kSendBeaconThrowForBlobWithNonSimpleType{
     "SendBeaconThrowForBlobWithNonSimpleType",