Sync trace time on Chrome OS (just like Android)

base/debug/trace_event_impl.cc

Index: base/debug/trace_event_impl.cc
diff --git a/base/debug/trace_event_impl.cc b/base/debug/trace_event_impl.cc
index 1f23c369014932f097753dd10af062693292f1fe..b23f5952664d08dabd3292b3b557bd0f65ec6b37 100644
--- a/base/debug/trace_event_impl.cc
+++ b/base/debug/trace_event_impl.cc
@@ -683,11 +683,11 @@ void TraceLog::AddTraceEventEtw(char phase,
 }
 
 void TraceLog::AddClockSyncMetadataEvents() {
-#if defined(OS_ANDROID)
-  // Since Android does not support sched_setaffinity, we cannot establish clock
-  // sync unless the scheduler clock is set to global. If the trace_clock file
-  // can't be read, we will assume the kernel doesn't support tracing and do
-  // nothing.
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS)
+  // Since Android/ChromeOS do not support sched_setaffinity, we cannot
+  // establish clock sync unless the scheduler clock is set to global.
+  // If the trace_clock file can't be read, we will assume the kernel
+  // doesn't support tracing and do nothing.
   std::string clock_mode;
   if (!file_util::ReadFileToString(
           FilePath("/sys/kernel/debug/tracing/trace_clock"),
@@ -702,7 +702,7 @@ void TraceLog::AddClockSyncMetadataEvents() {
     return;
   }
 
-  // Android's kernel trace system has a trace_marker feature: this is a file on
+  // Linux's kernel trace system has a trace_marker feature: this is a file on
   // debugfs that takes the written data and pushes it onto the trace
   // buffer. So, to establish clock sync, we write our monotonic clock into that
   // trace buffer.