WIP GPU scheduler + delayed activation / tile draw

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 09a17d465e08006a085a4398d3dfe10736e1f923..e327fd731dfe0bfd33e00445e4f549ef4fbb8ea7 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -385,6 +385,9 @@ const char kEnableWebFontsInterventionV2SwitchValueEnabledWithSlow2G[] =
     "enabled-slow2g";
 const char kEnableWebFontsInterventionV2SwitchValueDisabled[] = "disabled";
 
+// Enables GPU channel scheduler.
+const char kEnableGpuScheduler[] = "enable-gpu-scheduler";
+
 // Makes the GL worker context run asynchronously by using a separate stream.
 const char kEnableGpuAsyncWorkerContext[] = "enable-gpu-async-worker-context";