Remove CanChallengePlatform() and CheckPlatformState().

ppapi/thunk/ppb_platform_verification_api.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_THUNK_PPB_PLATFORM_VERIFICATION_API_H_
 #define PPAPI_THUNK_PPB_PLATFORM_VERIFICATION_API_H_
 
 #include "base/memory/ref_counted.h"
 #include "ppapi/thunk/ppapi_thunk_export.h"
 
 namespace ppapi {
 
 class TrackedCallback;
 
 namespace thunk {
 
 class PPAPI_THUNK_EXPORT PPB_PlatformVerification_API {
  public:
   virtual ~PPB_PlatformVerification_API() {}
 
-  virtual int32_t CanChallengePlatform(
-      PP_Bool* can_challenge_platform,
-      const scoped_refptr<TrackedCallback>& callback) = 0;
   virtual int32_t ChallengePlatform(
       const PP_Var& service_id,
       const PP_Var& challenge,
       PP_Var* signed_data,
       PP_Var* signed_data_signature,
       PP_Var* platform_key_certificate,
       const scoped_refptr<TrackedCallback>& callback) = 0;
 };
 
 }  // namespace thunk
 }  // namespace ppapi
 
 #endif  // PPAPI_THUNK_PPB_PLATFORM_VERIFICATION_API_H_