Support GCC 4.7

Removed constructors inheritance.
Removed emplace use.

Change-Id: I45224e3232d39ff22f758c7e387be2c9aff5eae0
Reviewed-on: https://weave-review.googlesource.com/1606
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
diff --git a/src/privet/wifi_ssid_generator_unittest.cc b/src/privet/wifi_ssid_generator_unittest.cc
index 398e105..10680c8 100644
--- a/src/privet/wifi_ssid_generator_unittest.cc
+++ b/src/privet/wifi_ssid_generator_unittest.cc
@@ -23,7 +23,7 @@
 };
 
 TEST_F(WifiSsidGeneratorTest, GenerateFlagsNoHostedAp) {
-  EXPECT_EQ(ssid_generator_.GenerateFlags().size(), 2);
+  EXPECT_EQ(ssid_generator_.GenerateFlags().size(), 2u);
 
   wifi_.connection_state_ = ConnectionState{ConnectionState::kUnconfigured};
   gcd_.connection_state_ = ConnectionState{ConnectionState::kUnconfigured};
@@ -42,7 +42,7 @@
 TEST_F(WifiSsidGeneratorTest, GenerateFlagsWithHostedAp) {
   EXPECT_CALL(wifi_, GetHostedSsid())
       .WillRepeatedly(Return(ssid_generator_.GenerateSsid()));
-  EXPECT_EQ(ssid_generator_.GenerateFlags().size(), 2);
+  EXPECT_EQ(ssid_generator_.GenerateFlags().size(), 2u);
 
   wifi_.connection_state_ = ConnectionState{ConnectionState::kUnconfigured};
   gcd_.connection_state_ = ConnectionState{ConnectionState::kUnconfigured};
@@ -59,7 +59,7 @@
 }
 
 TEST_F(WifiSsidGeneratorTest, GenerateSsid31orLess) {
-  EXPECT_LE(ssid_generator_.GenerateSsid().size(), 31);
+  EXPECT_LE(ssid_generator_.GenerateSsid().size(), 31u);
 }
 
 TEST_F(WifiSsidGeneratorTest, GenerateSsidValue) {