Turn on the squashing runtime setting if specified on the commandline.

BUG=

Review URL: https://codereview.chromium.org/282653002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270002 0039d316-1c4b-4281-b951-d872f2087c98

content/child/runtime_features.cc

@@ -155,6 +155,9 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
 
   if (command_line.HasSwitch(switches::kEnablePreciseMemoryInfo))
     WebRuntimeFeatures::enablePreciseMemoryInfo(true);
+
+  if (command_line.HasSwitch(switches::kEnableLayerSquashing))
+    WebRuntimeFeatures::enableLayerSquashing(true);
 }
 
 }  // namespace content