b=937057 provide a null ptr instead of a zero buffer when processing resampler tail r=padenot

--HG--
extra : transplant_source : %8EK%22q%A6%E9%82%F1%5E-%9E%BEs%01%F1%D1Jj%097

content/media/webaudio/MediaBufferDecoder.cpp

@@ -382,20 +382,12 @@ MediaDecodeTask::Decode()
   if (sampleRate != destSampleRate) {
     int inputLatency = speex_resampler_get_input_latency(resampler);
     int outputLatency = speex_resampler_get_output_latency(resampler);
-    AudioDataValue* zero = (AudioDataValue*)calloc(inputLatency, sizeof(AudioDataValue));
-
-    if (!zero) {
-      // Out of memory!
-      ReportFailureOnMainThread(WebAudioDecodeJob::UnknownError);
-      return;
-    }
-
     for (uint32_t i = 0; i < channelCount; ++i) {
       uint32_t inSamples = inputLatency;
       uint32_t outSamples = outputLatency;
 
       WebAudioUtils::SpeexResamplerProcess(
-          resampler, i, zero, &inSamples,
+          resampler, i, (AudioDataValue*)nullptr, &inSamples,
           mDecodeJob.mChannelBuffers[i] + mDecodeJob.mWriteIndex,
           &outSamples);
 
@@ -404,8 +396,6 @@ MediaDecodeTask::Decode()
         MOZ_ASSERT(mDecodeJob.mWriteIndex <= resampledFrames);
       }
     }
-
-    free(zero);
   }
 
   mPhase = PhaseEnum::AllocateBuffer;

content/media/webaudio/blink/HRTFElevation.cpp

@@ -137,12 +137,8 @@ nsReturnRef<HRTFKernel> HRTFElevation::calculateKernelForAzimuthElevation(int az
             // Feed in zeros get the data remaining in the resampler.
             spx_uint32_t out_index = out_len;
             in_len = speex_resampler_get_input_latency(resampler);
-            nsAutoTArray<AudioDataValue, 256> zeros;
-            zeros.SetLength(in_len);
-            PodZero(zeros.Elements(), in_len);
             out_len = resampled.Length() - out_index;
-            RESAMPLER_PROCESS(resampler, 0,
-                              zeros.Elements(), &in_len,
+            RESAMPLER_PROCESS(resampler, 0, nullptr, &in_len,
                               resampled.Elements() + out_index, &out_len);
             out_index += out_len;
             // There may be some uninitialized samples remaining for very low