Cleanup: Remove unneeded forward declarations in ppapi.

ppapi/proxy/proxy_channel.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_PROXY_CHANNEL_H_
 #define PPAPI_PROXY_PROXY_CHANNEL_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/process.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_platform_file.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 
 namespace base {
 class MessageLoopProxy;
 class WaitableEvent;
 }
 
 namespace IPC {
 class TestSink;
 }
 
 namespace ppapi {
 namespace proxy {
 
-class VarSerializationRules;
-
 class PPAPI_PROXY_EXPORT ProxyChannel
     : public IPC::Channel::Listener,
       public IPC::Message::Sender {
  public:
   typedef void (*ShutdownModuleFunc)();
 
   class PPAPI_PROXY_EXPORT Delegate {
    public:
     virtual ~Delegate() {}
 
@@ skipping 31 matching lines @@
   // Will be NULL in some unit tests and if the remote side has crashed.
   IPC::SyncChannel* channel() const {
     return channel_.get();
   }
 
 #if defined(OS_POSIX)
   int TakeRendererFD();
 #endif
 
  protected:
-  ProxyChannel(base::ProcessHandle remote_process_handle);
+  explicit ProxyChannel(base::ProcessHandle remote_process_handle);
 
   // You must call this function before anything else. Returns true on success.
   // The delegate pointer must outlive this class, ownership is not
   // transferred.
   virtual bool InitWithChannel(Delegate* delegate,
                                const IPC::ChannelHandle& channel_handle,
                                bool is_client);
 
   ProxyChannel::Delegate* delegate() const {
     return delegate_;
@@ skipping 14 matching lines @@
   // remote side has crashed.
   scoped_ptr<IPC::SyncChannel> channel_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyChannel);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PROXY_CHANNEL_H_