Add a |scope| argument to TRACE_EVENT_INSTANT* and require its presence.

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index f81a8769ed59fd8490c7b08cb8d758d3a25ac973..4808cc1ea265a9e02458d456a60872d4a60b52fe 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -82,7 +82,8 @@ void Compositor::Initialize() {
 void Compositor::InitializeWithFlags(uint32 flags) {
   g_use_direct_gl = flags & DIRECT_CONTEXT_ON_DRAW_THREAD;
   if (flags & ENABLE_COMPOSITOR_THREAD) {
-    TRACE_EVENT_INSTANT0("test_gpu", "ThreadedCompositingInitialization");
+    TRACE_EVENT_INSTANT0("test_gpu", "ThreadedCompositingInitialization",
+                         TRACE_EVENT_SCOPE_THREAD);
     g_impl_thread = new webkit_glue::WebThreadImpl("Browser Compositor");
   }
   Compositor::Initialize();