Replace NULL with nullptr in all C++ files.

webrtc/voice_engine/voe_hardware_impl.cc

Index: webrtc/voice_engine/voe_hardware_impl.cc
diff --git a/webrtc/voice_engine/voe_hardware_impl.cc b/webrtc/voice_engine/voe_hardware_impl.cc
index 1748fc2309d81bd6edc4c067c1d84c8eba0c8768..815954bcd709979b09ba6ebedf1ba2827e2c557f 100644
--- a/webrtc/voice_engine/voe_hardware_impl.cc
+++ b/webrtc/voice_engine/voe_hardware_impl.cc
@@ -19,8 +19,8 @@
 namespace webrtc {
 
 VoEHardware* VoEHardware::GetInterface(VoiceEngine* voiceEngine) {
-  if (NULL == voiceEngine) {
-    return NULL;
+  if (nullptr == voiceEngine) {
+    return nullptr;
   }
   VoiceEngineImpl* s = static_cast<VoiceEngineImpl*>(voiceEngine);
   s->AddRef();
@@ -145,13 +145,13 @@ int VoEHardwareImpl::GetRecordingDeviceName(int index,
     _shared->SetLastError(VE_NOT_INITED, kTraceError);
     return -1;
   }
-  if (strNameUTF8 == NULL) {
+  if (strNameUTF8 == nullptr) {
     _shared->SetLastError(VE_INVALID_ARGUMENT, kTraceError,
                           "GetRecordingDeviceName() invalid argument");
     return -1;
   }
 
-  // Note that strGuidUTF8 is allowed to be NULL
+  // Note that strGuidUTF8 is allowed to be null
 
   // Init len variable to length of supplied vectors
   const uint16_t strLen = 128;
@@ -173,7 +173,7 @@ int VoEHardwareImpl::GetRecordingDeviceName(int index,
   // Copy to vectors supplied by user
   strncpy(strNameUTF8, name, strLen);
 
-  if (strGuidUTF8 != NULL) {
+  if (strGuidUTF8 != nullptr) {
     strncpy(strGuidUTF8, guid, strLen);
   }
 
@@ -187,13 +187,13 @@ int VoEHardwareImpl::GetPlayoutDeviceName(int index,
     _shared->SetLastError(VE_NOT_INITED, kTraceError);
     return -1;
   }
-  if (strNameUTF8 == NULL) {
+  if (strNameUTF8 == nullptr) {
     _shared->SetLastError(VE_INVALID_ARGUMENT, kTraceError,
                           "GetPlayoutDeviceName() invalid argument");
     return -1;
   }
 
-  // Note that strGuidUTF8 is allowed to be NULL
+  // Note that strGuidUTF8 is allowed to be null
 
   // Init len variable to length of supplied vectors
   const uint16_t strLen = 128;
@@ -215,7 +215,7 @@ int VoEHardwareImpl::GetPlayoutDeviceName(int index,
   // Copy to vectors supplied by user
   strncpy(strNameUTF8, name, strLen);
 
-  if (strGuidUTF8 != NULL) {
+  if (strGuidUTF8 != nullptr) {
     strncpy(strGuidUTF8, guid, strLen);
   }