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

ppapi/proxy/dispatcher.h

Index: ppapi/proxy/dispatcher.h
diff --git a/ppapi/proxy/dispatcher.h b/ppapi/proxy/dispatcher.h
index 348c91c29076669686c541ce30a59ea7da62b5d4..1c7ef384f079812b1d1f66ede0fc6d0a24dd0f09 100644
--- a/ppapi/proxy/dispatcher.h
+++ b/ppapi/proxy/dispatcher.h
@@ -21,10 +21,9 @@
 #include "ppapi/proxy/plugin_var_tracker.h"
 
 namespace ppapi {
+
 class WebKitForwarding;
-}
 
-namespace pp {
 namespace proxy {
 
 class VarSerializationRules;
@@ -119,6 +118,6 @@ class Dispatcher : public ProxyChannel {
 };
 
 }  // namespace proxy
-}  // namespace pp
+}  // namespace ppapi
 
 #endif  // PPAPI_PROXY_DISPATCHER_H_