shill: Replace VLOG with SLOG.

This CL replaces all uses of VLOG(level) with SLOG(scope, level) with
the same verbose level and an appropriate scope for each affected
logging statement.

BUG=chromium-os:29641
TEST=Build and run unit tests. Test scope logging with ff_debug.

Change-Id: Ifdcf1faa2a309bcbd9ee369a66179ce9c7f1ad19
Reviewed-on: https://gerrit.chromium.org/gerrit/20629
Commit-Ready: Ben Chan <benchan@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
diff --git a/ethernet.cc b/ethernet.cc
index 91ec170..65997a3 100644
--- a/ethernet.cc
+++ b/ethernet.cc
@@ -22,6 +22,7 @@
 #include "shill/manager.h"
 #include "shill/profile.h"
 #include "shill/rtnl_handler.h"
+#include "shill/scope_logger.h"
 
 using std::string;
 
@@ -44,7 +45,7 @@
              Technology::kEthernet),
       service_registered_(false),
       link_up_(false) {
-  VLOG(2) << "Ethernet device " << link_name << " initialized.";
+  SLOG(Ethernet, 2) << "Ethernet device " << link_name << " initialized.";
 }
 
 Ethernet::~Ethernet() {