Reland: Implement Aura side of unified touch text selection for contents

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..8adeb4874e6aa21065226d86963e0a3530729288 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -59,7 +59,6 @@ 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);
@@ -67,6 +66,10 @@ static void SetRuntimeFeatureDefaultsForPlatform() {
   WebRuntimeFeatures::enableNavigatorContentUtils(true);
 #endif  // defined(OS_ANDROID)
 
+#if defined(OS_ANDROID) || defined(USE_AURA)
+  WebRuntimeFeatures::enableCompositedSelectionUpdate(true);
+#endif
+
 #if !(defined OS_ANDROID || defined OS_CHROMEOS || defined OS_IOS)
     // Only Android, ChromeOS, and IOS support NetInfo right now.
     WebRuntimeFeatures::enableNetworkInformation(false);