Add a path to use CALayers to display content

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 68745deb4c11b3c9581c0cc1f84b900e4ac19847..8932e19d11fe02d28fecf1051ffe5b277e431f97 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -797,6 +797,9 @@ const char kChildCleanExit[]                = "child-clean-exit";
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 const char kDisableCarbonInterposing[]      = "disable-carbon-interposing";
+
+// Use core animation to draw the RenderWidgetHostView on Mac.
+const char kUseCoreAnimation[]              = "use-core-animation";
 #endif
 
 // Disables the use of a 3D software rasterizer.