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

cc/animation.cc

 // Copyright 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 "cc/animation.h"
 
 #include <cmath>
 
 #include "base/debug/trace_event.h"
 #include "base/string_util.h"
@@ skipping 84 matching lines @@
     m_runState = runState;
 
     const char* newRunStateName = s_runStateNames[runState];
 
     if (!wasFinished && isFinished())
         TRACE_EVENT_ASYNC_END0("cc", "Animation", this);
 
     char stateBuffer[256];
     base::snprintf(stateBuffer, sizeof(stateBuffer), "%s->%s", oldRunStateName, newRunStateName);
 
-    TRACE_EVENT_INSTANT2("cc", "LayerAnimationController::setRunState", "Name", TRACE_STR_COPY(nameBuffer), "State", TRACE_STR_COPY(stateBuffer));
+    TRACE_EVENT_INSTANT2("cc", "LayerAnimationController::setRunState",
+                         TRACE_EVENT_SCOPE_THREAD,
+                         "Name", TRACE_STR_COPY(nameBuffer),
+                         "State", TRACE_STR_COPY(stateBuffer));
 }
 
 void Animation::suspend(double monotonicTime)
 {
     setRunState(Paused, monotonicTime);
     m_suspended = true;
 }
 
 void Animation::resume(double monotonicTime)
 {
@@ skipping 85 matching lines @@
 {
     // Currently, we only push changes due to pausing and resuming animations on the main thread.
     if (m_runState == Animation::Paused || other->m_runState == Animation::Paused) {
         other->m_runState = m_runState;
         other->m_pauseTime = m_pauseTime;
         other->m_totalPausedTime = m_totalPausedTime;
     }
 }
 
 }  // namespace cc