arc: enable Android tracing in verified-boot mode

content/browser/tracing/tracing_controller_impl.cc

 // Copyright (c) 2013 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/tracing/tracing_controller_impl.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 580 matching lines @@
     const std::string& events_label,
     const scoped_refptr<base::RefCountedString>& events_str_ptr) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (trace_data_sink_.get() && events_str_ptr &&
       !events_str_ptr->data().empty()) {
     if (agent_name == kETWTracingAgentName) {
       // The Windows kernel events are kept into a JSON format stored as string
       // and must not be escaped.
       trace_data_sink_->AddAgentTrace(events_label, events_str_ptr->data());
-    } else if (agent_name != kArcTracingAgentName) {
-      // ARC trace data is obtained via systrace. Ignore the empty data.
-      // Quote other trace data as JSON strings and merge them into
-      // |trace_data_sink_|.
+    } else if (agent_name == kArcTracingAgentName) {
+      // The ARC events are kept into a JSON format stored as string
+      // and must not be escaped.
+      trace_data_sink_->AddTraceChunk(events_str_ptr->data());
+    } else {
       trace_data_sink_->AddAgentTrace(
           events_label, base::GetQuotedJSONString(events_str_ptr->data()));
     }
   }
   std::vector<std::string> category_groups;
   OnStopTracingAcked(NULL, category_groups);
 }
 
 void TracingControllerImpl::OnTraceDataCollected(
     const scoped_refptr<base::RefCountedString>& events_str_ptr) {
@@ skipping 301 matching lines @@
 void TracingControllerImpl::RemoveTraceMessageFilterObserver(
     TraceMessageFilterObserver* observer) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   trace_message_filter_observers_.RemoveObserver(observer);
 
   for (auto& filter : trace_message_filters_)
     observer->OnTraceMessageFilterRemoved(filter.get());
 }
 
 }  // namespace content