Replace NULL with nullptr in all C++ files.

webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc

Index: webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc
diff --git a/webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc b/webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc
index 7f5bb03e719ed4cc08ce54e1158fc36b5738ef5e..720aa7cad8b101d606ac5ddc746f5e0344890acd 100644
--- a/webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc
+++ b/webrtc/modules/audio_processing/transient/dyadic_decimator_unittest.cc
@@ -33,18 +33,16 @@ TEST(DyadicDecimatorTest, GetOutLengthToDyadicDecimate) {
 TEST(DyadicDecimatorTest, DyadicDecimateErrorValues) {
   size_t out_samples = 0;
 
-  out_samples = DyadicDecimate(static_cast<int16_t*>(NULL),
-                               kEvenBufferLength,
-                               false,  // Even sequence.
-                               test_buffer_out,
-                               kOutBufferLength);
+  out_samples =
+      DyadicDecimate(static_cast<int16_t*>(nullptr), kEvenBufferLength,
+                     false,  // Even sequence.
+                     test_buffer_out, kOutBufferLength);
   EXPECT_EQ(0u, out_samples);
 
-  out_samples = DyadicDecimate(test_buffer_even_len,
-                               kEvenBufferLength,
-                               false,  // Even sequence.
-                               static_cast<int16_t*>(NULL),
-                               kOutBufferLength);
+  out_samples =
+      DyadicDecimate(test_buffer_even_len, kEvenBufferLength,
+                     false,  // Even sequence.
+                     static_cast<int16_t*>(nullptr), kOutBufferLength);
   EXPECT_EQ(0u, out_samples);
 
   // Less than required |out_length|.