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

blimp/client/session/blimp_client_session_linux.h

Index: blimp/client/session/blimp_client_session_linux.h
diff --git a/blimp/client/session/blimp_client_session_linux.h b/blimp/client/session/blimp_client_session_linux.h
index 2cd86246af21c0e88e313558003df170a25aa00e..bee3ad9ac3fadf54c8b963dc6a32864a24e2a6c2 100644
--- a/blimp/client/session/blimp_client_session_linux.h
+++ b/blimp/client/session/blimp_client_session_linux.h
@@ -14,6 +14,7 @@ class PlatformEventSource;
 }
 
 namespace blimp {
+namespace client {
 
 class BlimpClientSessionLinux : public BlimpClientSession,
                                 public BlimpDisplayManagerDelegate {
@@ -31,6 +32,7 @@ class BlimpClientSessionLinux : public BlimpClientSession,
   DISALLOW_COPY_AND_ASSIGN(BlimpClientSessionLinux);
 };
 
+}  // namespace client
 }  // namespace blimp
 
 #endif  // BLIMP_CLIENT_SESSION_BLIMP_CLIENT_SESSION_LINUX_H_