Route selection bounds updates through WebLayerTreeView

Source/core/frame/Settings.in

Index: Source/core/frame/Settings.in
diff --git a/Source/core/frame/Settings.in b/Source/core/frame/Settings.in
index c9d121e1d15ba57f14d8327dacfb7293ea814b25..24a2e43b56691baaa2018e7e6fd6226e47ba8de1 100644
--- a/Source/core/frame/Settings.in
+++ b/Source/core/frame/Settings.in
@@ -208,6 +208,10 @@ wideViewportQuirkEnabled initial=false
 # crbug.com/304873 tracks removal once it's been enabled on all platforms.
 touchEditingEnabled initial=false
 
+# Used for composited selection handle positioning and visibility testing.
+# See http://crbug.com/135959
+compositedSelectionUpdatesEnabled initial=false
+
 # Settings for experimental desktop pinch-zoom support (with semantics
 # optimized for large screens).  Pinch-zoom generally is implemented mainly
 # outside of blink (in the compositor) and doesn't require any settings.