Remove redundancies of multiply() in FFTFrame.

Source/platform/audio/FFTFrame.cpp

Index: Source/platform/audio/FFTFrame.cpp
diff --git a/Source/platform/audio/FFTFrame.cpp b/Source/platform/audio/FFTFrame.cpp
index 58df785fbd2f3cb7da97c2625d5ba5c05b34e670..806a148d30cfbfc3e0c7ea78e6205f9608055a7a 100644
--- a/Source/platform/audio/FFTFrame.cpp
+++ b/Source/platform/audio/FFTFrame.cpp
@@ -32,6 +32,8 @@
 
 #include "platform/audio/FFTFrame.h"
 
+#include "platform/audio/VectorMath.h"
+
 #ifndef NDEBUG
 #include <stdio.h>
 #endif
@@ -259,6 +261,27 @@ void FFTFrame::addConstantGroupDelay(double sampleFrameDelay)
     }
 }
 
+void FFTFrame::multiply(const FFTFrame& frame)
+{
+    FFTFrame& frame1 = *this;
+    FFTFrame& frame2 = const_cast<FFTFrame&>(frame);
+
+    float* realP1 = frame1.realData();
+    float* imagP1 = frame1.imagData();
+    const float* realP2 = frame2.realData();
+    const float* imagP2 = frame2.imagData();
+
+    unsigned halfSize = fftSize() / 2;
+    float real0 = realP1[0];
+    float imag0 = imagP1[0];
+
+    VectorMath::zvmul(realP1, imagP1, realP2, imagP2, realP1, imagP1, halfSize);
+
+    // Multiply the packed DC/nyquist component
+    realP1[0] = real0 * realP2[0];
+    imagP1[0] = imag0 * imagP2[0];
+}
+
 #ifndef NDEBUG
 void FFTFrame::print()
 {