[Experimental, WIP] Demo version of extracting WebView selection data from CompositorFrame.

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index 830941534a1a1aec11794f4a2ddab8bbadd08437..98e3be439ce2a98aa86f5bd36e354f6986565706 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -59,13 +59,13 @@ static void SetRuntimeFeatureDefaultsForPlatform() {
   WebRuntimeFeatures::enableOrientationEvent(true);
   WebRuntimeFeatures::enableFastMobileScrolling(true);
   WebRuntimeFeatures::enableMediaCapture(true);
-  WebRuntimeFeatures::enableCompositedSelectionUpdate(true);
   // Android won't be able to reliably support non-persistent notifications, the
   // intended behavior for which is in flux by itself.
   WebRuntimeFeatures::enableNotificationConstructor(false);
 #else
   WebRuntimeFeatures::enableNavigatorContentUtils(true);
 #endif  // defined(OS_ANDROID)
+  WebRuntimeFeatures::enableCompositedSelectionUpdate(true);
 
 #if !(defined OS_ANDROID || defined OS_CHROMEOS || defined OS_IOS)
     // Only Android, ChromeOS, and IOS support NetInfo right now.