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

content/browser/gpu/gpu_process_host.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/gpu/gpu_process_host.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 456 matching lines @@
   BlockLiveOffscreenContexts();
 
   BrowserThread::PostTask(BrowserThread::UI,
                           FROM_HERE,
                           base::Bind(&GpuProcessHostUIShim::Destroy, host_id_));
 }
 
 bool GpuProcessHost::Init() {
   init_start_time_ = base::TimeTicks::Now();
 
-  TRACE_EVENT_INSTANT0("gpu", "LaunchGpuProcess");
+  TRACE_EVENT_INSTANT0("gpu", "LaunchGpuProcess", TRACE_EVENT_SCOPE_THREAD);
 
   std::string channel_id = process_->GetHost()->CreateChannel();
   if (channel_id.empty())
     return false;
 
   if (in_process_) {
     CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kDisableGpuWatchdog);
 
     in_process_gpu_thread_.reset(new GpuMainThread(channel_id));
@@ skipping 570 matching lines @@
 void GpuProcessHost::BlockLiveOffscreenContexts() {
   for (std::multiset<GURL>::iterator iter =
            urls_with_live_offscreen_contexts_.begin();
        iter != urls_with_live_offscreen_contexts_.end(); ++iter) {
     GpuDataManagerImpl::GetInstance()->BlockDomainFrom3DAPIs(
         *iter, GpuDataManagerImpl::DOMAIN_GUILT_UNKNOWN);
   }
 }
 
 }  // namespace content