Replace NULL with nullptr in all C++ files.

webrtc/modules/audio_processing/vad/standalone_vad_unittest.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 49 matching lines @@
 #else
 TEST(StandaloneVadTest, ActivityDetection) {
 #endif
   std::unique_ptr<StandaloneVad> vad(StandaloneVad::Create());
   const size_t kDataLength = kLength10Ms;
   int16_t data[kDataLength] = {0};
 
   FILE* pcm_file =
       fopen(test::ResourcePath("audio_processing/agc/agc_audio", "pcm").c_str(),
             "rb");
-  ASSERT_TRUE(pcm_file != NULL);
+  ASSERT_TRUE(pcm_file != nullptr);
 
   FILE* reference_file = fopen(
       test::ResourcePath("audio_processing/agc/agc_vad", "dat").c_str(), "rb");
-  ASSERT_TRUE(reference_file != NULL);
+  ASSERT_TRUE(reference_file != nullptr);
 
   // Reference activities are prepared with 0 aggressiveness.
   ASSERT_EQ(0, vad->set_mode(0));
 
   // Stand-alone VAD can operate on 1, 2 or 3 frames of length 10 ms. The
   // reference file is created for 30 ms frame.
   const int kNumVadFramesToProcess = 3;
   int num_frames = 0;
   while (fread(data, sizeof(int16_t), kDataLength, pcm_file) == kDataLength) {
     vad->AddAudio(data, kDataLength);
@@ skipping 14 matching lines @@
         // When inactive, probabilities are set to 0.01.
         for (int n = 0; n < kNumVadFramesToProcess; n++)
           EXPECT_EQ(0.01, p[n]);
       }
     }
   }
   fclose(reference_file);
   fclose(pcm_file);
 }
 }  // namespace webrtc