[Blimp client] Move client code into blimp::client namespace

blimp/client/session/navigation_feature_unittest.cc

Index: blimp/client/session/navigation_feature_unittest.cc
diff --git a/blimp/client/session/navigation_feature_unittest.cc b/blimp/client/session/navigation_feature_unittest.cc
index e73965276b030b5c3ef7dc55343fef6286990581..fb154e6618639a792d6790e8f2781dd8ee778049 100644
--- a/blimp/client/session/navigation_feature_unittest.cc
+++ b/blimp/client/session/navigation_feature_unittest.cc
@@ -18,6 +18,7 @@
 using testing::_;
 
 namespace blimp {
+namespace client {
 
 class MockNavigationFeatureDelegate
     : public NavigationFeature::NavigationFeatureDelegate {
@@ -155,4 +156,5 @@ TEST_F(NavigationFeatureTest, TestNavigateReloadMessage) {
   feature_.Reload(1);
 }
 
+}  // namespace client
 }  // namespace blimp