Issue #1484 - Make PassthroughAPP a pass-through again

src/plugin/PluginWbPassThrough.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 66 matching lines @@
 
   STDMETHODIMP ReportResult(
     /* [in] */ HRESULT hrResult,
     /* [in] */ DWORD dwError,
     /* [in] */ LPCWSTR szResult);
 
   STDMETHODIMP Switch(
     /* [in] */ PROTOCOLDATA *pProtocolData);
 };
 
-class WBPassthru;
-typedef PassthroughAPP::CustomSinkStartPolicy<WBPassthru, WBPassthruSink> WBStartPolicy;
+class WbPassthroughProtocol;
 
-class WBPassthru : public PassthroughAPP::CInternetProtocol<WBStartPolicy>
+class WbPassthroughSinkStartPolicy
+  : public PassthroughAPP::CustomSinkStartPolicy<WbPassthroughProtocol, WBPassthruSink>
 {
-  typedef PassthroughAPP::CInternetProtocol<WBStartPolicy> BaseClass;
+  typedef PassthroughAPP::CustomSinkStartPolicy<WbPassthroughProtocol, WBPassthruSink> BaseClass;
 public:
-  WBPassthru();
-  // IInternetProtocolRoot
+  HRESULT OnStart(LPCWSTR szUrl,
+    IInternetProtocolSink *pOIProtSink, IInternetBindInfo *pOIBindInfo,
+    DWORD grfPI, HANDLE_PTR dwReserved,
+    IInternetProtocol* pTargetProtocol);
+};
+
+/**
+ * Implementation of "Protocol" interfaces
+ */
+class WbPassthroughProtocol
+  : public PassthroughAPP::CInternetProtocol<WbPassthroughSinkStartPolicy>
+{
+  typedef PassthroughAPP::CInternetProtocol<WbPassthroughSinkStartPolicy> BaseClass;
+public:
+  WbPassthroughProtocol()
+    : m_shouldSupplyCustomContent(false)
+  {
+  }
+
+  // derived from IInternetProtocolRoot
   STDMETHODIMP Start(LPCWSTR szUrl, IInternetProtocolSink *pOIProtSink,
     IInternetBindInfo *pOIBindInfo, DWORD grfPI, HANDLE_PTR dwReserved) override;
 
-  // IInternetProtocol
+  // derived from IInternetProtocol
   STDMETHODIMP Read(/* [in, out] */ void *pv,/* [in] */ ULONG cb,/* [out] */ ULONG *pcbRead) override;
 
   bool m_shouldSupplyCustomContent;
 };
+
+typedef PassthroughAPP::CMetaFactory<PassthroughAPP::CComClassFactoryProtocol, WbPassthroughProtocol> MetaFactory;
+
+