Mojo C++ bindings: more consistent Clone() and Equals().

mojo/public/cpp/bindings/associated_interface_ptr_info.h

 // Copyright 2015 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 MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_
 
 #include <stdint.h>
 #include <utility>
 
@@ skipping 39 matching lines @@
     return std::move(handle_);
   }
   const ScopedInterfaceEndpointHandle& handle() const { return handle_; }
   void set_handle(ScopedInterfaceEndpointHandle handle) {
     handle_ = std::move(handle);
   }
 
   uint32_t version() const { return version_; }
   void set_version(uint32_t version) { version_ = version; }
 
+  bool Equals(const AssociatedInterfacePtrInfo& other) const {
+    if (this == &other)
+      return true;
+
+    // Now that the two refer to different objects, they are equivalent if
+    // and only if they are both invalid.
+    return !is_valid() && !other.is_valid();
+  }
+
  private:
   ScopedInterfaceEndpointHandle handle_;
   uint32_t version_;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_