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

cc/trees/thread_proxy.cc

 // Copyright 2011 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/trees/thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "cc/base/thread.h"
@@ skipping 806 matching lines @@
   layer_tree_host_->BeginCommitOnImplThread(layer_tree_host_impl_.get());
   layer_tree_host_->FinishCommitOnImplThread(layer_tree_host_impl_.get());
   layer_tree_host_impl_->CommitComplete();
 
   next_frame_is_newly_committed_frame_on_impl_thread_ = true;
 
   if (layer_tree_host_->settings().impl_side_painting &&
       layer_tree_host_->BlocksPendingCommit()) {
     // For some layer types in impl-side painting, the commit is held until
     // the pending tree is activated.
-    TRACE_EVENT_INSTANT0("cc", "HoldCommit");
+    TRACE_EVENT_INSTANT0("cc", "HoldCommit", TRACE_EVENT_SCOPE_THREAD);
     completion_event_for_commit_held_on_tree_activation_ =
         commit_completion_event_on_impl_thread_;
     commit_completion_event_on_impl_thread_ = NULL;
   } else {
     commit_completion_event_on_impl_thread_->Signal();
     commit_completion_event_on_impl_thread_ = NULL;
   }
 
   // SetVisible kicks off the next scheduler action, so this must be last.
   scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
@@ skipping 65 matching lines @@
     layer_tree_host_impl_->DrawLayers(
         &frame,
         scheduler_on_impl_thread_->LastVSyncTime());
     result.did_draw= true;
   }
   layer_tree_host_impl_->DidDrawAllLayers(frame);
 
   // Check for tree activation.
   if (completion_event_for_commit_held_on_tree_activation_ &&
       !layer_tree_host_impl_->pending_tree()) {
-    TRACE_EVENT_INSTANT0("cc", "ReleaseCommitbyActivation");
+    TRACE_EVENT_INSTANT0("cc", "ReleaseCommitbyActivation",
+                         TRACE_EVENT_SCOPE_THREAD);
     DCHECK(layer_tree_host_impl_->settings().impl_side_painting);
     completion_event_for_commit_held_on_tree_activation_->Signal();
     completion_event_for_commit_held_on_tree_activation_ = NULL;
   }
 
   // Check for a pending CompositeAndReadback.
   if (readback_request_on_impl_thread_) {
     readback_request_on_impl_thread_->success = false;
     if (draw_frame) {
       layer_tree_host_impl_->Readback(readback_request_on_impl_thread_->pixels,
@@ skipping 387 matching lines @@
       base::Bind(&ThreadProxy::StartScrollbarAnimationOnImplThread,
                  impl_thread_weak_ptr_),
       delay);
 }
 
 void ThreadProxy::StartScrollbarAnimationOnImplThread() {
   layer_tree_host_impl_->StartScrollbarAnimation(base::TimeTicks::Now());
 }
 
 }  // namespace cc