PVS-Studio warning V557 for Chromium

#define FRAMESAMPLES_HALF      240
#define FRAMESAMPLES           480

typedef struct {
  ...
  WebRtc_Word16 realFFT[FRAMESAMPLES_HALF];
  WebRtc_Word16 imagFFT[FRAMESAMPLES_HALF];
} ISACUBSaveEncDataStruct;

int WebRtcIsac_EncodeStoredDataUb12(....)
{
  ...
  for(n = 0; n < FRAMESAMPLES; n++)
  {
    realFFT[n] = (WebRtc_Word16)
      (scale * (float)ISACSavedEnc_obj->realFFT[n] + 0.5f);
    imagFFT[n] = (WebRtc_Word16)
      (scale * (float)ISACSavedEnc_obj->imagFFT[n] + 0.5f);
  }
  ...
}

This suspicious code was found in Chromium project by PVS-Studio static code analyzer.
Warning message is:
V557 Array overrun is possible. The value of 'n' index could reach 479. iSAC encode.c 1307

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/