Convert the pp::proxy namespace to the ppapi::proxy namespace.

ppapi/proxy/ppb_file_system_proxy.cc

Index: ppapi/proxy/ppb_file_system_proxy.cc
diff --git a/ppapi/proxy/ppb_file_system_proxy.cc b/ppapi/proxy/ppb_file_system_proxy.cc
index b3035b972fbd2cd5bfd818ac0e4be7dd179fb4ee..899c51f82821641f8c394acc71a4886217af2f3f 100644
--- a/ppapi/proxy/ppb_file_system_proxy.cc
+++ b/ppapi/proxy/ppb_file_system_proxy.cc
@@ -18,13 +18,11 @@
 #include "ppapi/thunk/resource_creation_api.h"
 #include "ppapi/thunk/thunk.h"
 
-using ppapi::HostResource;
-using ppapi::Resource;
 using ppapi::thunk::EnterFunctionNoLock;
 using ppapi::thunk::PPB_FileSystem_API;
 using ppapi::thunk::ResourceCreationAPI;
 
-namespace pp {
+namespace ppapi {
 namespace proxy {
 
 namespace {
@@ -123,7 +121,7 @@ PPB_FileSystem_Proxy::~PPB_FileSystem_Proxy() {
 
 const InterfaceProxy::Info* PPB_FileSystem_Proxy::GetInfo() {
   static const Info info = {
-    ::ppapi::thunk::GetPPB_FileSystem_Thunk(),
+    thunk::GetPPB_FileSystem_Thunk(),
     PPB_FILESYSTEM_INTERFACE,
     INTERFACE_ID_PPB_FILE_SYSTEM,
     false,
@@ -197,4 +195,4 @@ void PPB_FileSystem_Proxy::OpenCompleteInHost(
 }
 
 }  // namespace proxy
-}  // namespace pp
+}  // namespace ppapi