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

content/common/gpu/image_transport_surface.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.
 
 #include "content/common/gpu/image_transport_surface.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 50 matching lines @@
     IPC_MESSAGE_HANDLER(AcceleratedSurfaceMsg_ResizeViewACK, OnResizeViewACK);
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void ImageTransportHelper::SendAcceleratedSurfaceBuffersSwapped(
     GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params) {
   // TRACE_EVENT for gpu tests:
   TRACE_EVENT_INSTANT2("test_gpu", "SwapBuffers",
+                       TRACE_EVENT_SCOPE_THREAD,
                        "GLImpl", static_cast<int>(gfx::GetGLImplementation()),
                        "width", params.size.width());
   params.surface_id = stub_->surface_id();
   params.route_id = route_id_;
 #if defined(OS_MACOSX)
   params.window = handle_;
 #endif
   manager_->Send(new GpuHostMsg_AcceleratedSurfaceBuffersSwapped(params));
 }
 
@@ skipping 220 matching lines @@
 void PassThroughImageTransportSurface::SendVSyncUpdateIfAvailable() {
   gfx::VSyncProvider* vsync_provider = GetVSyncProvider();
   if (vsync_provider) {
     vsync_provider->GetVSyncParameters(
       base::Bind(&ImageTransportHelper::SendUpdateVSyncParameters,
                  helper_->AsWeakPtr()));
   }
 }
 
 }  // namespace content