shill: Makes scan-type message a LOG(INFO)

As progressive scan gets rolled-out, it'll be really useful to know
whether a bug was seen in the presence of progressive or full scan.
This CL modifies the logging such that every shill-instigated scan is
logged with the scan type at the LOG(INFO) level.

BUG=None
TEST=unittest

Change-Id: I19763c84f5b4dda6a8a9daba056bfe1096064ccd
Reviewed-on: https://gerrit.chromium.org/gerrit/59992
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Queue: Wade Guthrie <wdg@chromium.org>
Reviewed-by: Wade Guthrie <wdg@chromium.org>
Tested-by: Wade Guthrie <wdg@chromium.org>
diff --git a/wifi.cc b/wifi.cc
index d5ed6f2..26025d1 100644
--- a/wifi.cc
+++ b/wifi.cc
@@ -308,7 +308,7 @@
     metrics()->NotifyDeviceScanStarted(interface_index());
   }
   if (progressive_scan_enabled_ && scan_type == kProgressiveScan) {
-    SLOG(WiFi, 4) << "Doing progressive scan on " << link_name();
+    LOG(INFO) << "Doing progressive scan on " << link_name();
     if (!scan_session_) {
       // TODO(wdg): Perform in-depth testing to determine the best values for
       // the different scans. chromium:235293
@@ -337,8 +337,8 @@
     dispatcher()->PostTask(
         Bind(&WiFi::ProgressiveScanTask, weak_ptr_factory_.GetWeakPtr()));
   } else {
-    SLOG(WiFi, 4) << "Doing full scan - progressive scan "
-                  << (progressive_scan_enabled_ ? "ENABLED" : "DISABLED");
+    LOG(INFO) << "Doing full scan on " << link_name() << " - progressive scan "
+              << (progressive_scan_enabled_ ? "ENABLED" : "DISABLED");
     // Needs to send a D-Bus message, but may be called from D-Bus
     // signal handler context (via Manager::RequestScan). So defer work
     // to event loop.