Move FuzzedDataProvider to //base and expose to blink

net/base/fuzzed_data_provider.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/base/fuzzed_data_provider.h"
-
-#include <algorithm>
-#include <limits>
-
-#include "base/logging.h"
-
-namespace net {
-
-FuzzedDataProvider::FuzzedDataProvider(const uint8_t* data, size_t size)
-    : remaining_data_(reinterpret_cast<const char*>(data), size) {}
-
-FuzzedDataProvider::~FuzzedDataProvider() {}
-
-base::StringPiece FuzzedDataProvider::ConsumeBytes(size_t num_bytes) {
-  num_bytes = std::min(num_bytes, remaining_data_.length());
-  base::StringPiece result(remaining_data_.data(), num_bytes);
-  remaining_data_ = remaining_data_.substr(num_bytes);
-  return result;
-}
-
-base::StringPiece FuzzedDataProvider::ConsumeRemainingBytes() {
-  return ConsumeBytes(remaining_data_.length());
-}
-
-uint32_t FuzzedDataProvider::ConsumeUint32InRange(uint32_t min, uint32_t max) {
-  CHECK_LE(min, max);
-
-  uint32_t range = max - min;
-  uint32_t offset = 0;
-  uint32_t result = 0;
-
-  while ((range >> offset) > 0 && !remaining_data_.empty()) {
-    // Pull bytes off the end of the seed data. Experimentally, this seems to
-    // allow the fuzzer to more easily explore the input space. This makes
-    // sense, since it works by modifying inputs that caused new code to run,
-    // and this data is often used to encode length of data read by
-    // ConsumeBytes. Separating out read lengths makes it easier modify the
-    // contents of the data that is actually read.
-    uint8_t next_byte = remaining_data_.back();
-    remaining_data_.remove_suffix(1);
-    result = (result << 8) | next_byte;
-    offset += 8;
-  }
-
-  // Avoid division by 0, in the case |range + 1| results in overflow.
-  if (range == std::numeric_limits<uint32_t>::max())
-    return result;
-
-  return min + result % (range + 1);
-}
-
-int FuzzedDataProvider::ConsumeInt32InRange(int min, int max) {
-  CHECK_LE(min, max);
-
-  uint32_t range = max - min;
-  return min + ConsumeUint32InRange(0, range);
-}
-
-bool FuzzedDataProvider::ConsumeBool() {
-  return (ConsumeUint8() & 0x01) == 0x01;
-}
-
-uint8_t FuzzedDataProvider::ConsumeUint8() {
-  return ConsumeUint32InRange(0, 0xFF);
-}
-
-uint16_t FuzzedDataProvider::ConsumeUint16() {
-  return ConsumeUint32InRange(0, 0xFFFF);
-}
-
-}  // namespace net