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

blimp/client/compositor/blimp_output_surface.cc

Index: blimp/client/compositor/blimp_output_surface.cc
diff --git a/blimp/client/compositor/blimp_output_surface.cc b/blimp/client/compositor/blimp_output_surface.cc
index 7c2836e844a13dc15195ebd695570d15d2a32bc9..1c671bb6f3677bd82a50b66b2fabfaa9889952cd 100644
--- a/blimp/client/compositor/blimp_output_surface.cc
+++ b/blimp/client/compositor/blimp_output_surface.cc
@@ -10,6 +10,7 @@
 #include "gpu/command_buffer/client/context_support.h"
 
 namespace blimp {
+namespace client {
 
 BlimpOutputSurface::BlimpOutputSurface(
     const scoped_refptr<cc::ContextProvider>& context_provider)
@@ -25,4 +26,5 @@ void BlimpOutputSurface::SwapBuffers(cc::CompositorFrame* frame) {
   cc::OutputSurface::PostSwapBuffersComplete();
 }
 
+}  // namespace client
 }  // namespace blimp