Use std::function instead of base::Callback in net/http2/.

net/http2/tools/random_decoder_test.cc

 // Copyright 2016 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.
 
 #include "net/http2/tools/random_decoder_test.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 109 matching lines @@
         << "\nFailed with SelectZeroAndOne";
     VERIFY_EQ(first_consumed, input.Offset())
         << "\nFailed with SelectZeroAndOne; input.Offset=" << input.Offset()
         << "; input.Remaining=" << input.Remaining();
   }
   {
     // Decode again, with randomly selected segment sizes.
     DecodeBuffer input(original->cursor(), original_remaining);
     VLOG(2) << "DecodeSegmentsAndValidate with SelectRandom";
     VERIFY_SUCCESS(DecodeSegmentsAndValidate(
-        &input, RandomDecoderTest::SelectRandom(return_non_zero_on_first),
-        validator))
+        &input, SelectRandom(return_non_zero_on_first), validator))
         << "\nFailed with SelectRandom; input.Offset=" << input.Offset()
         << "; input.Remaining=" << input.Remaining();
     VERIFY_EQ(first_consumed, input.Offset()) << "\nFailed with SelectRandom";
   }
   VERIFY_EQ(original_remaining, original->Remaining());
   original->AdvanceCursor(first_consumed);
   VLOG(1) << "DecodeAndValidateSeveralWays - SUCCESS";
   return ::testing::AssertionSuccess();
 }
 
@@ skipping 28 matching lines @@
     return r % (remaining + 1);  // size in range [0, remaining].
   };
 }
 
 uint32_t RandomDecoderTest::RandStreamId() {
   return random_.Rand32() & StreamIdMask();
 }
 
 }  // namespace test
 }  // namespace net