Stop exposing --disable-gpu-compositing as a Blink RuntimeEnabledFeature

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index aabfc6a843ab221dd799a9d9e2b9a9ce9b7baf2b..bdfdf825322b0f4076d517de8ac632b9f971f932 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -685,6 +685,12 @@ bool RendererBlinkPlatformImpl::isThreadedCompositingEnabled() {
   return thread && thread->compositor_task_runner().get();
 }
 
+bool RendererBlinkPlatformImpl::isGPUCompositingEnabled() {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  return !command_line.HasSwitch(switches::kDisableGpuCompositing);
+}
+
 bool RendererBlinkPlatformImpl::isThreadedAnimationEnabled() {
   RenderThreadImpl* thread = RenderThreadImpl::current();
   return thread ? thread->IsThreadedAnimationEnabled() : true;