Remove CanChallengePlatform() and CheckPlatformState().

ppapi/cpp/private/platform_verification.h

 // Copyright 2013 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_PRIVATE_PLATFORM_VERIFICATION_H_
 #define PPAPI_CPP_PRIVATE_PLATFORM_VERIFICATION_H_
 
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/cpp/resource.h"
 
 namespace pp {
 
 class InstanceHandle;
 class Var;
 
 class PlatformVerification : public Resource {
  public:
   explicit PlatformVerification(const InstanceHandle& instance);
   virtual ~PlatformVerification();
 
-  int32_t CanChallengePlatform(
-      const CompletionCallbackWithOutput<bool>& callback);
   int32_t ChallengePlatform(const Var& service_id,
                             const Var& challenge,
                             Var* signed_data,
                             Var* signed_data_signature,
                             Var* platform_key_certificate,
                             const CompletionCallback& callback);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_PRIVATE_PLATFORM_VERIFICATION_H_