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

blimp/client/session/render_widget_feature.h

Index: blimp/client/session/render_widget_feature.h
diff --git a/blimp/client/session/render_widget_feature.h b/blimp/client/session/render_widget_feature.h
index fb2f7aec656f1fd7b24561d001564a4c70717689..2982acc0cd2e4730bca6b41cd35dde8ce9d404ae 100644
--- a/blimp/client/session/render_widget_feature.h
+++ b/blimp/client/session/render_widget_feature.h
@@ -25,6 +25,7 @@ class CompositorMessage;
 }
 
 namespace blimp {
+namespace client {
 
 // Handles all incoming and outgoing protobuf message types tied to a specific
 // RenderWidget. This includes BlimpMessage::INPUT, BlimpMessage::COMPOSITOR,
@@ -103,6 +104,7 @@ class BLIMP_CLIENT_EXPORT RenderWidgetFeature : public BlimpMessageProcessor {
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetFeature);
 };
 
+}  // namespace client
 }  // namespace blimp
 
 #endif  // BLIMP_CLIENT_SESSION_RENDER_WIDGET_FEATURE_H_