shill: cellular: Modify traffic monitor to look at send-q and timer status.

BUG=chromium:225912
TEST=Unit tests

Change-Id: I6585e5860f0043d6c2b8d1ef6502834b18219abf
Reviewed-on: https://gerrit.chromium.org/gerrit/47446
Commit-Queue: Thieu Le <thieule@chromium.org>
Reviewed-by: Thieu Le <thieule@chromium.org>
Tested-by: Thieu Le <thieule@chromium.org>
diff --git a/mock_ipconfig.h b/mock_ipconfig.h
index a20ece0..42358c6 100644
--- a/mock_ipconfig.h
+++ b/mock_ipconfig.h
@@ -20,6 +20,7 @@
                const std::string &device_name);
   virtual ~MockIPConfig();
 
+  MOCK_CONST_METHOD0(properties, const Properties &(void));
   MOCK_METHOD0(RequestIP, bool(void));
   MOCK_METHOD0(RenewIP, bool(void));
   MOCK_METHOD0(ReleaseIP, bool(void));
@@ -30,6 +31,10 @@
                           const std::string &id_suffix));
 
  private:
+  const Properties &real_properties() {
+    return IPConfig::properties();
+  }
+
   DISALLOW_COPY_AND_ASSIGN(MockIPConfig);
 };