Replace NULL with nullptr in all C++ files.

webrtc/voice_engine/test/auto_test/standard/mixing_test.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 93 matching lines @@
     if (!real_audio) {
       VerifyMixedOutput(max_output_value, min_output_value);
     }
   }
 
  private:
   // Generate input file with constant values equal to |input_value|. The file
   // will be twice the duration of the test.
   void GenerateInputFile(int16_t input_value) {
     FILE* input_file = fopen(input_filename_.c_str(), "wb");
-    ASSERT_TRUE(input_file != NULL);
+    ASSERT_TRUE(input_file != nullptr);
     for (int i = 0; i < kInSampleRateHz / 1000 * (kTestDurationMs * 2); i++) {
       ASSERT_EQ(1u, fwrite(&input_value, sizeof(input_value), 1, input_file));
     }
     ASSERT_EQ(0, fclose(input_file));
   }
 
   void VerifyMixedOutput(int16_t max_output_value, int16_t min_output_value) {
     // Verify the mixed output.
     FILE* output_file = fopen(output_filename_.c_str(), "rb");
-    ASSERT_TRUE(output_file != NULL);
+    ASSERT_TRUE(output_file != nullptr);
     int16_t output_value = 0;
     int samples_read = 0;
     while (fread(&output_value, sizeof(output_value), 1, output_file) == 1) {
       samples_read++;
       std::ostringstream trace_stream;
       trace_stream << samples_read << " samples read";
       SCOPED_TRACE(trace_stream.str());
       ASSERT_LE(output_value, max_output_value);
       ASSERT_GE(output_value, min_output_value);
     }
@@ skipping 61 matching lines @@
     for (size_t i = 0; i < streams.size(); ++i) {
       EXPECT_EQ(0, voe_base_->StopSend(streams[i]));
       EXPECT_EQ(0, voe_base_->StopPlayout(streams[i]));
       EXPECT_EQ(0, voe_network_->DeRegisterExternalTransport(streams[i]));
       EXPECT_EQ(0, voe_base_->DeleteChannel(streams[i]));
     }
   }
 
   int GetFileDurationMs(const char* file_name) {
     FILE* fid = fopen(file_name, "rb");
-    EXPECT_FALSE(fid == NULL);
+    EXPECT_FALSE(fid == nullptr);
     fseek(fid, 0, SEEK_END);
     int size = ftell(fid);
     EXPECT_NE(-1, size);
     fclose(fid);
     // Divided by 2 due to 2 bytes/sample.
     return size * 1000 / kRecSampleRateHz / 2;
   }
 
   std::string input_filename_;
   const std::string output_filename_;
@@ skipping 60 matching lines @@
 
 TEST_F(MixingTest, VerifyStereoAndMonoMixing) {
   const int16_t kInputValue = 1000;
   const int16_t kExpectedOutput = kInputValue * 2;
   RunMixingTest(2, 0, 1, false, kInputValue, 1.1 * kExpectedOutput,
                 // Lower than 0.9 due to observed flakiness on bots.
                 0.8 * kExpectedOutput, kCodecL16);
 }
 
 }  // namespace webrtc