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

ui/gl/gl_surface_glx.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 #include "ui/gl/gl_surface_glx.h"
 
@@ skipping 179 matching lines @@
 
       if (!context_ || cancel_vsync_flag_.IsSet())
         return;
 
       glXMakeCurrent(display_, window_, context_);
 
       unsigned int retrace_count = 0;
       if (glXWaitVideoSyncSGI(1, 0, &retrace_count) != 0)
         return;
 
-      TRACE_EVENT_INSTANT0("gpu", "vblank");
+      TRACE_EVENT_INSTANT0("gpu", "vblank", TRACE_EVENT_SCOPE_THREAD);
       now = base::TimeTicks::HighResNow();
 
       glXMakeCurrent(display_, 0, 0);
     }
 
     const base::TimeDelta kDefaultInterval =
         base::TimeDelta::FromSeconds(1) / 60;
 
     message_loop_->PostTask(
         FROM_HERE, base::Bind(callback, now, kDefaultInterval));
@@ skipping 211 matching lines @@
   return true;
 }
 
 bool NativeViewGLSurfaceGLX::IsOffscreen() {
   return false;
 }
 
 bool NativeViewGLSurfaceGLX::SwapBuffers() {
   glXSwapBuffers(g_display, window_);
   // For latency_tests.cc:
-  UNSHIPPED_TRACE_EVENT_INSTANT0("test_gpu", "CompositorSwapBuffersComplete");
+  UNSHIPPED_TRACE_EVENT_INSTANT0("test_gpu", "CompositorSwapBuffersComplete",
+                                 TRACE_EVENT_SCOPE_THREAD);
   return true;
 }
 
 gfx::Size NativeViewGLSurfaceGLX::GetSize() {
   return size_;
 }
 
 void* NativeViewGLSurfaceGLX::GetHandle() {
   return reinterpret_cast<void*>(window_);
 }
@@ skipping 171 matching lines @@
 
 void* PbufferGLSurfaceGLX::GetConfig() {
   return config_;
 }
 
 PbufferGLSurfaceGLX::~PbufferGLSurfaceGLX() {
   Destroy();
 }
 
 }  // namespace gfx