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

content/browser/browser_main_loop.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/browser/browser_main_loop.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/hi_res_timer_manager.h"
@@ skipping 724 matching lines @@
   ui::Clipboard::SetAllowedThreads(allowed_clipboard_threads);
 
   // When running the GPU thread in-process, avoid optimistically starting it
   // since creating the GPU thread races against creation of the one-and-only
   // ChildProcess instance which is created by the renderer thread.
   if (GpuDataManagerImpl::GetInstance()->GpuAccessAllowed() &&
       IsForceCompositingModeEnabled() &&
       !parsed_command_line_.HasSwitch(switches::kDisableGpuProcessPrelaunch) &&
       !parsed_command_line_.HasSwitch(switches::kSingleProcess) &&
       !parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
-    TRACE_EVENT_INSTANT0("gpu", "Post task to launch GPU process");
+    TRACE_EVENT_INSTANT0("gpu", "Post task to launch GPU process",
+                         TRACE_EVENT_SCOPE_THREAD);
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE, base::Bind(
             base::IgnoreResult(&GpuProcessHost::Get),
             GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
             CAUSE_FOR_GPU_LAUNCH_BROWSER_STARTUP));
   }
 #endif  // !defined(OS_IOS)
 }
 
 void BrowserMainLoop::InitializeToolkit() {
@@ skipping 49 matching lines @@
   DCHECK_EQ(MessageLoop::TYPE_UI, MessageLoop::current()->type());
   if (parameters_.ui_task)
     MessageLoopForUI::current()->PostTask(FROM_HERE, *parameters_.ui_task);
 
   base::RunLoop run_loop;
   run_loop.Run();
 #endif
 }
 
 }  // namespace content