Add a switch to enable compositing for scrollable frames.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 08e55fa42e5c674b171f9b399907a036cb7a113c..b551191703d657acfc5483116bfbbde574efb283 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -581,8 +581,13 @@ const char kShowFPSCounter[]                = "show-fps-counter";
 
 // Enables accelerated compositing for overflow scroll. Promotes eligible
 // overflow:scroll elements to layers to enable accelerated scrolling for them.
-const char kEnableAcceleratedCompositingForOverflowScroll[] =
-    "enable-accelerated-compositing-for-overflow-scroll";
+const char kEnableAcceleratedOverflowScroll[] =
+    "enable-accelerated-overflow-scroll";
+
+// Enables accelerated compositing for scrollable frames for accelerated
+// scrolling for them.
+const char kEnableAcceleratedScrollableFrames[] =
+     "enable-accelerated-scrollable-frames";
 
 // Visibly render a border around paint rects in the web page to help debug
 // and study painting behavior.