Cleanup: Remove unneeded forward declarations in ppapi.

ppapi/proxy/enter_proxy.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PPAPI_PROXY_ENTER_PROXY_H_
 #define PPAPI_PROXY_ENTER_PROXY_H_
 
 #include "base/logging.h"
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_globals.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/thunk/enter.h"
 
 namespace ppapi {
 
-namespace thunk {
-class ResourceCreationAPI;
-}
-
 namespace proxy {
 
 // Wrapper around EnterResourceNoLock that takes a host resource. This is used
 // when handling messages in the plugin from the host and we need to convert to
 // an object in the plugin side corresponding to that.
 //
 // This never locks since we assume the host Resource is coming from IPC, and
 // never logs errors since we assume the host is doing reasonable things.
 template<typename ResourceT>
 class EnterPluginFromHostResource
     : public thunk::EnterResourceNoLock<ResourceT> {
  public:
-  EnterPluginFromHostResource(const HostResource& host_resource)
+  explicit EnterPluginFromHostResource(const HostResource& host_resource)
       : thunk::EnterResourceNoLock<ResourceT>(
             PluginGlobals::Get()->plugin_resource_tracker()->
                 PluginResourceForHostResource(host_resource),
             false) {
     // Validate that we're in the plugin rather than the host. Otherwise this
     // object will do the wrong thing. In the plugin, the instance should have
     // a corresponding plugin dispatcher (assuming the resource is valid).
     DCHECK(this->failed() ||
            PluginDispatcher::GetForInstance(host_resource.instance()));
   }
 };
 
 template<typename ResourceT>
 class EnterHostFromHostResource
     : public thunk::EnterResourceNoLock<ResourceT> {
  public:
-  EnterHostFromHostResource(const HostResource& host_resource)
+  explicit EnterHostFromHostResource(const HostResource& host_resource)
       : thunk::EnterResourceNoLock<ResourceT>(
             host_resource.host_resource(), false) {
     // Validate that we're in the host rather than the plugin. Otherwise this
     // object will do the wrong thing. In the host, the instance should have
     // a corresponding host disptacher (assuming the resource is valid).
     DCHECK(this->failed() ||
            HostDispatcher::GetForInstance(host_resource.instance()));
   }
 };
 
@@ skipping 177 matching lines @@
   }
 
   bool needs_running_;
   pp::CompletionCallback callback_;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_ENTER_PROXY_H_