Convert resources to take an instance key instead of an Instance*.

ppapi/cpp/resource.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_CPP_RESOURCE_H_
 #define PPAPI_CPP_RESOURCE_H_
 
 #include "ppapi/c/pp_resource.h"
+#include "ppapi/cpp/instance_handle.h"
+#include "ppapi/cpp/pass_ref.h"
 
 /// @file
 /// This file defines a <code>Resource</code> type representing data associated
 /// with the module.
 namespace pp {
 
 /// A reference counted module resource.
 class Resource {
  public:
-
   /// The default constructor.
   Resource();
 
   /// A constructor for copying a resource.
   ///
   /// @param[in] other A <code>Resource</code>.
   Resource(const Resource& other);
 
   /// Destructor.
   virtual ~Resource();
@@ skipping 24 matching lines @@
   PP_Resource detach();
 
  protected:
   /// A constructor used when a <code>PP_Resource</code> is provided as a
   /// return value whose reference count we need to increment.
   ///
   /// @param[in] resource A <code>PP_Resource</code> corresponding to a
   /// resource.
   explicit Resource(PP_Resource resource);
 
+  /// Constructor used when a <code>PP_Resource</code> already has a ref count
+  /// assigned. Add additional refcount is not taken.
+  Resource(PassRef, PP_Resource resource);
+
   /// PassRefFromConstructor is called by derived class' constructors to
   /// initialize this <code>Resource</code> with a <code>PP_Resource</code>
   /// that has already had its reference count incremented by
   /// <code>Core::AddRefResource</code>. It also assumes this object has no
   /// current resource.
   ///
   /// The intended usage of this function that the derived class constructor
   /// will call the default <code>Resource</code> constructor, then make a call
   /// to create a resource. It then wants to assign the new resource (which,
   /// since it was returned by the browser, already had its reference count
   /// increased).
   ///
   /// @param[in] resource A <code>PP_Resource</code> corresponding to a
   /// resource.
   void PassRefFromConstructor(PP_Resource resource);
 
  private:
   PP_Resource pp_resource_;
 };
 
 }  // namespace pp
 
 inline bool operator==(const pp::Resource& lhs, const pp::Resource& rhs) {
   return lhs.pp_resource() == rhs.pp_resource();
 }
 
 #endif // PPAPI_CPP_RESOURCE_H_