Add TRACE_EVENT macros to net (after crrev.com/1834273002)

net/base/address_tracker_linux.cc

Index: net/base/address_tracker_linux.cc
diff --git a/net/base/address_tracker_linux.cc b/net/base/address_tracker_linux.cc
index 59d732c90d79f60a4690cb6278ae1a974b36e6dc..2365ff16decfde19da74cccb0b24e265c786e5ae 100644
--- a/net/base/address_tracker_linux.cc
+++ b/net/base/address_tracker_linux.cc
@@ -13,6 +13,7 @@
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/trace_event/trace_event.h"
 #include "net/base/network_interfaces_linux.h"
 
 namespace net {
@@ -413,6 +414,7 @@ void AddressTrackerLinux::HandleMessage(char* buffer,
 }
 
 void AddressTrackerLinux::OnFileCanReadWithoutBlocking(int fd) {
+  TRACE_EVENT0("net", "AddressTrackerLinux::OnFileCanReadWithoutBlocking");
   DCHECK_EQ(netlink_fd_, fd);
   bool address_changed;
   bool link_changed;