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/virtio_ethernet.cc b/virtio_ethernet.cc
index 0e400e0..d748871 100644
--- a/virtio_ethernet.cc
+++ b/virtio_ethernet.cc
@@ -13,6 +13,7 @@
 #include "shill/control_interface.h"
 #include "shill/event_dispatcher.h"
 #include "shill/manager.h"
+#include "shill/scope_logger.h"
 
 using std::string;
 
@@ -32,7 +33,7 @@
                link_name,
                address,
                interface_index) {
-  VLOG(2) << "VirtioEthernet device " << link_name << " initialized.";
+  SLOG(Ethernet, 2) << "VirtioEthernet device " << link_name << " initialized.";
 }
 
 VirtioEthernet::~VirtioEthernet() {
@@ -52,9 +53,9 @@
   // transmit any frames. (See crosbug.com/29494)
   //
   // To avoid this, we sleep to let the device setup function complete.
-  VLOG(2) << "Sleeping to let virtio initialize.";
+  SLOG(Ethernet, 2) << "Sleeping to let virtio initialize.";
   sleep(2);
-  VLOG(2) << "Starting virtio Ethernet.";
+  SLOG(Ethernet, 2) << "Starting virtio Ethernet.";
   Ethernet::Start(error, callback);
 }