Use nullptr instead of 0 in WebAudio

Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp

Index: Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
diff --git a/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp b/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
index 319eba5cf69e0af6cc84d5d7562770f7b0601ccc..d578f2276085777532d7bae37412ebb70813a5af 100644
--- a/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
+++ b/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
@@ -54,8 +54,8 @@ FFTFrame::FFTFrame(unsigned fftSize)
     , m_log2FFTSize(static_cast<unsigned>(log2(fftSize)))
     , m_realData(fftSize / 2)
     , m_imagData(fftSize / 2)
-    , m_forwardContext(0)
-    , m_inverseContext(0)
+    , m_forwardContext(nullptr)
+    , m_inverseContext(nullptr)
     , m_complexData(fftSize)
 {
     // We only allow power of two.
@@ -69,8 +69,8 @@ FFTFrame::FFTFrame(unsigned fftSize)
 FFTFrame::FFTFrame()
     : m_FFTSize(0)
     , m_log2FFTSize(0)
-    , m_forwardContext(0)
-    , m_inverseContext(0)
+    , m_forwardContext(nullptr)
+    , m_inverseContext(nullptr)
 {
 }
 
@@ -80,8 +80,8 @@ FFTFrame::FFTFrame(const FFTFrame& frame)
     , m_log2FFTSize(frame.m_log2FFTSize)
     , m_realData(frame.m_FFTSize / 2)
     , m_imagData(frame.m_FFTSize / 2)
-    , m_forwardContext(0)
-    , m_inverseContext(0)
+    , m_forwardContext(nullptr)
+    , m_inverseContext(nullptr)
     , m_complexData(frame.m_FFTSize)
 {
     m_forwardContext = contextForSize(m_FFTSize, DFT_R2C);