Make remaining parts of components/metrics use metrics namespace.

components/metrics/net/wifi_access_point_info_provider.h

Index: components/metrics/net/wifi_access_point_info_provider.h
diff --git a/components/metrics/net/wifi_access_point_info_provider.h b/components/metrics/net/wifi_access_point_info_provider.h
index 5d74c3c5c2011c7a210cd7b591e121a956b49cb9..349375695b7d1a20383c7c37e9175185483ab75d 100644
--- a/components/metrics/net/wifi_access_point_info_provider.h
+++ b/components/metrics/net/wifi_access_point_info_provider.h
@@ -8,6 +8,8 @@
 #include <string>
 #include "base/basictypes.h"
 
+namespace metrics {
+
 // Interface for accessing connected wireless access point information.
 class WifiAccessPointInfoProvider {
  public:
@@ -46,4 +48,6 @@ class WifiAccessPointInfoProvider {
   DISALLOW_COPY_AND_ASSIGN(WifiAccessPointInfoProvider);
 };
 
+}  // namespace metrics
+
 #endif  // COMPONENTS_METRICS_NET_WIFI_ACCESS_POINT_INFO_PROVIDER_H_