Display warning when dumping audio if file exists

Source/Core/AudioCommon/WaveFile.cpp

@@ -24,6 +24,20 @@ WaveFileWriter::~WaveFileWriter()
 
 bool WaveFileWriter::Start(const std::string& filename, unsigned int HLESampleRate)
 {
+  // Ask to delete file
+  if (File::Exists(filename))
+  {
+    if (AskYesNoT("Delete the existing file '%s'?", filename.c_str()))
+    {
+      File::Delete(filename);
+    }
+    else
+    {
+      // Stop and cancel dumping the audio
+      return false;
+    }
+  }
+
   // Check if the file is already open
   if (file)
   {