Add --v switch into example code

Change-Id: I872dd0d910ec892a8ed23220fe66db49984f8ec0
Reviewed-on: https://weave-review.googlesource.com/1281
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
diff --git a/libweave/examples/ubuntu/main.cc b/libweave/examples/ubuntu/main.cc
index 5a7c2fa..0891e01 100644
--- a/libweave/examples/ubuntu/main.cc
+++ b/libweave/examples/ubuntu/main.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include <bitset>
+
 #include <base/bind.h>
 #include <base/values.h>
 #include <weave/device.h>
@@ -25,6 +26,7 @@
   LOG(ERROR) << "\nUsage: " << name << " <option(s)>"
              << "\nOptions:\n"
              << "\t-h,--help                    Show this help message\n"
+             << "\t--v=LEVEL                    Logging level\n"
              << "\t-b,--bootstrapping           Force WiFi bootstrapping\n"
              << "\t-d,--disable_security        Disable privet security\n"
              << "\t--registration_ticket=TICKET Register device with the "
@@ -249,6 +251,13 @@
         return 1;
       }
       registration_ticket = arg.substr(pos + 1);
+    } else if (arg.find("--v") != std::string::npos) {
+      auto pos = arg.find("=");
+      if (pos == std::string::npos) {
+        ShowUsage(argv[0]);
+        return 1;
+      }
+      logging::SetMinLogLevel(-std::stoi(arg.substr(pos + 1)));
     } else {
       ShowUsage(argv[0]);
       return 1;
diff --git a/libweave/external/base/logging.cc b/libweave/external/base/logging.cc
index c576d18..1fd047f 100644
--- a/libweave/external/base/logging.cc
+++ b/libweave/external/base/logging.cc
@@ -83,11 +83,6 @@
   return std::max(-1, LOG_INFO - GetMinLogLevel());
 }
 
-int GetVlogLevelHelper(const char* file, size_t N) {
-  DCHECK_GT(N, 0U);
-  return 0;
-}
-
 void SetLogItems(bool enable_process_id, bool enable_thread_id,
                  bool enable_timestamp, bool enable_tickcount) {
   g_log_timestamp = enable_timestamp;
diff --git a/libweave/external/base/logging.h b/libweave/external/base/logging.h
index 0096d9d..61e9f9d 100644
--- a/libweave/external/base/logging.h
+++ b/libweave/external/base/logging.h
@@ -195,7 +195,9 @@
 // __FILE__).
 
 // Note that |N| is the size *with* the null terminator.
-int GetVlogLevelHelper(const char* file_start, size_t N);
+inline int GetVlogLevelHelper(const char* file_start, size_t N) {
+  return GetVlogVerbosity();
+}
 
 template <size_t N>
 int GetVlogLevel(const char (&file)[N]) {