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

blimp/client/linux/blimp_display_manager.h

Index: blimp/client/linux/blimp_display_manager.h
diff --git a/blimp/client/linux/blimp_display_manager.h b/blimp/client/linux/blimp_display_manager.h
index 8927dc1dee6c474938b24d144282595abc4bb7b1..bbdd92f32eda6395069cfd3376e2ab0610524242 100644
--- a/blimp/client/linux/blimp_display_manager.h
+++ b/blimp/client/linux/blimp_display_manager.h
@@ -18,6 +18,7 @@ class PlatformWindow;
 }
 
 namespace blimp {
+namespace client {
 
 class BlimpCompositor;
 class RenderWidgetFeature;
@@ -61,6 +62,7 @@ class BlimpDisplayManager : public ui::PlatformWindowDelegate {
   DISALLOW_COPY_AND_ASSIGN(BlimpDisplayManager);
 };
 
+}  // namespace client
 }  // namespace blimp
 
 #endif  // BLIMP_CLIENT_LINUX_BLIMP_DISPLAY_MANAGER_H_